Unveiling architectural and geometric dimensions through a systematic review of Córdoba: insights to UNESCO World Heritage Sites

The architectural and geometric significance of UNESCO World Heritage Sites is central to understanding their cultural and historical importance. These sites are not only recognized for their exceptional universal value, but they also embody the rich architectural and spatial traditions of the cultures that created them. Spanning a wide range of periods, regions, and architectural styles, these sites offer invaluable insights into the evolution of human civilization, from ancient architectural feats to the intricate planning of urban landscapes (Anelli and Tajani, 2022). As such, the preservation and analysis of their architectural and geometric dimensions are essential for both maintaining their integrity and deepening our understanding of the cultural narratives they represent (Li et al., 2021). Despite the recognition of their value, the preservation and analysis of these sites have been challenged by rapid urbanization, environmental change, and the pressures of tourism, which often result in a conflict between maintaining authenticity and accommodating contemporary needs (González Martínez, 2017; Handzic and Dimitrijevic, 2024). Addressing these challenges requires a comprehensive framework that not only considers cultural and historical significance but also integrates architectural and geometric elements into the conservation process.

In recent years, scholars and heritage practitioners have increasingly recognized the need for interdisciplinary approaches to heritage conservation, combining traditional methods with emerging technologies (Santana Quintero et al., 2020). Architectural and geometric analyses, which were once largely visual and descriptive, have evolved through the application of digital tools such as 3D modelling, laser scanning, and geographic information systems (GIS) (Hidalgo Fernández and Ortiz-Cordero, 2020; Petrovski et al., 2024). These technologies have transformed the way we understand the design, construction, and spatial relationships within heritage sites, offering more precise and measurable data for conservation and restoration efforts. For instance, advanced modelling techniques can uncover hidden or damaged architectural features, enabling a more accurate representation of a site’s original form (Storeide et al., 2023). These technological advancements offer tremendous potential for creating detailed documentation, supporting more effective interventions, and enhancing the understanding of how architecture interacts with its surrounding environment (Cho et al., 2022). Based on the explored case study of Córdoba, the present review highlights the growing importance of advanced digital tools such as 3D modelling, digital reconstructions, and imaging technologies in the study of architectural heritage. These innovations enable researchers to conduct more precise and comprehensive analyses of geometric patterns, construction techniques, and architectural evolution, significantly enhancing our understanding of these sites. When combined with traditional methodologies, these technologies mark a transformative shift in how cultural heritage is studied and preserved.

Previous research has underscored the significance of interdisciplinary approaches to heritage conservation; however, the absence of a standardized system for systematically assessing these sites has impeded the formulation of effective conservation strategies (Hyslop, 2023). Moreover, no comprehensive reviews have been conducted regarding architectural and geometric analysis within the context of UNESCO World Heritage Sites. A consistent framework for evaluating the existing research—or the lack thereof—on the architecture and geometry of these sites remains absent. This gap in the literature provides a valuable opportunity for a thorough synthesis, which could inform and direct future research in this field. In line with Loulanski and Loulanski’s (2011) meta-study on the sustainable integration of cultural heritage and tourism, which identifies significant research gaps in both tourism and cultural heritage studies, this paper aims to fill a similar void in the architectural and geometric analysis of UNESCO World Heritage Sites. This methodological framework can not only address the gaps identified in the literature but also offer a replicable approach for future interdisciplinary research across diverse cultural contexts. It provides a detailed framework for analysing architectural heritage research, using the city of Córdoba as a base for providing results, due to its UNESCO World Heritage status and its rich architectural and cultural significance. The methodology employed is based on a systematic review following the PRISMA 2020 protocol, ensuring a rigorous and transparent approach to data collection and analysis. While Córdoba serves as a case study for the present research, the methodology is designed to be replicable, making it applicable to any UNESCO World Heritage site. The proposed framework enables researchers to identify recurring dimensions and assess whether certain aspects of the architectural and geometric heritage of a site have received less attention or require further exploration. The novelty of this study lies in the identification of eight recurring dimensions from the existing literature, offering a structured approach to understanding how architectural and geometric elements contribute to the heritage value of UNESCO sites. These dimensions include: (1) Evaluation of architectural quality and restoration, (2) Analysis of geometry and architectural patterns, (3) Conservation and architectural changes, (4) Symbolism and recurring themes, (5) Exploration of cultural and social influence, (6) Construction techniques and urbanism, (7) Historical, archaeological, and evolutionary perspectives, and (8) Assessment of heritage and UNESCO criteria. By organizing future research around these dimensions, this study sets a new precedent for examining the architectural literature of UNESCO sites in a way that is both systematic and replicable, offering a framework that can be used universally by researchers worldwide.

By applying this replicable methodology, this study contributes to the global discourse on the preservation of UNESCO World Heritage Sites. Through a systematic review of the existing literature on Córdoba’s architectural heritage, a number of key categories have been established that can be used to classify research on heritage sites worldwide. These findings highlight recurring themes and gaps in the research, offering valuable insights that can inform future studies and, indirectly, support conservation strategies at both local and international levels.

This systematic review was conducted in accordance with the PRISMA 2020 guidelines (“PRISMA statement”, n.d.; PRISMA 2020 is employed in this systematic review to ensure methodological rigor, transparency, and reproducibility. The PRISMA 2020 guidelines provide a structured framework that covers all critical stages of the review process, including search strategy, study selection, data extraction, and synthesis, thereby reducing the risk of bias. This protocol enhances the clarity of reporting, facilitating critical appraisal and replication of the findings by other researchers. The updated PRISMA 2020 also integrates recent advancements in systematic review methodology, ensuring alignment with contemporary standards and maximizing the validity and reliability of the results. The 27 items included in the PRISMA methodology have been considered in the present work, see Figure 1. In this regard, the first step taken was to develop a review protocol in order to outline the search. This protocol serves to delineate the methods intended for review and helps in minimizing bias and enhancing consistency throughout the review process. In developing this protocol, the PRISMA-P 2015 checklist was followed. The checklist has therefore suggested items that should be addressed in a systematic review protocol. Two researchers screened the protocol checklist for the inclusion or exclusion of each item. In case of disagreements, agreement was reached upon by discussing it, and when essential a third researcher was consulted. The registration of the protocol y public and it can be found at the following link: Link to the website. Additionally, the protocol can be found in Annex 1.

The systematic review aims to address the research question: “What topics and perspectives have been explored in the existing literature on the architecture and geometry of Córdoba’s UNESCO World Heritage Sites?”. To comprehensively address this question, the SPICE framework (Setting, Perspective, Intervention, Comparison, Evaluation) is utilized to define and organize the scope of the review, ensuring a focused and systematic analysis of relevant studies. The eligibility criteria for including studies in this review are as follows:

1. Setting (S): Studies must focus on the Historic Centre, Medina Azahara, and the Cathedral Mosque in Córdoba, all recognized for their historical and cultural significance.

2. Perspective (P): Studies must be conducted from the perspectives of researchers, historians, architects, conservationists, or scholars with a focus on architectural history, aesthetics, or cultural heritage.

3. Intervention (I): The review will include studies that examine and analyse various aspects of architectural styles, aesthetic principles, and geometric patterns present in the selected sites. This includes the examination of design elements, construction techniques, materials used, decorative motifs, use of colour, integration of natural elements, spatial organization, symmetry, proportions, and mathematical principles.

4. Comparison (C): Studies should provide insights into the architectural styles, aesthetic principles, and geometric patterns of the Historic Centre, Medina Azahara, and Cathedral Mosque. While direct comparative analyses among these sites are valuable, studies that offer in-depth examinations of individual sites and discuss their architectural or geometric significance in relation to broader historical or cultural contexts will also be included. This means that research does not necessarily need to perform direct comparisons but should contribute to understanding how these aspects are represented and how they reflect the sites' historical and cultural contexts.

5. Evaluation (E): Eligible studies should provide a detailed description and analysis of the architectural, aesthetic, and geometric features of the sites, reflecting their historical and cultural contexts. This includes identifying common themes, differences, and unique aspects of each site, as well as discussing implications for preservation and future research.

The relevant studies for this research were identified through a comprehensive search conducted in October 2024. The search was performed across three key databases: Scopus (“Scopus - Document search”, n.d.), Web of Science Core Collection (“Web of Science Core Collection”, n.d.), and Dialnet (“Dialnet”, n.d.). Dialnet was included due to its significant focus on Spanish scholarship, which complements the coverage provided by the international bibliographic databases Scopus and Web of Science Core Collection.

Figure 2 illustrates the screening process according to the PRISMA flow diagram. The figure is segmented to reflect the three databases consulted: SCOPUS, Web of Science, and Dialnet. A total of 27 studies were retrieved from SCOPUS, 19 studies from Web of Science, and 34 studies from Dialnet. Literature was screened based on abstracts, by means of the search terms ABS ((Medina AND Azahara AND architecture) OR (Córdoba AND Madinat al Zahra AND geometry) OR (Córdoba AND Madinat al Zahra AND architecture) OR (Córdoba AND Historic AND centre) OR (Córdoba AND Cathedral AND Mosque AND geometry) OR (Córdoba AND Cathedral AND Mosque AND architecture) OR (UNESCO AND heritage AND Córdoba AND architecture) OR (Islamic AND architecture AND Córdoba)). Each search term was independently assessed to confirm its relevance. Once verified, all search terms were combined for a comprehensive search. To avoid retrieving duplicate documents, “OR” was used to separate each term. This strategy minimizes redundancy and ensures a more efficient retrieval of pertinent documents.

Since it is an investigation of an exploratory nature, no date restriction was applied. The planned limits were as follows:

1. Geographic Focus: The review is specifically focussed on UNESCO World Heritage Sites located in Córdoba. This includes all designated sites within the geographical boundaries of Córdoba.

2. Architectural and Geometric Scope: The review concentrates on studies that address architectural features and geometric design elements of the UNESCO Heritage Sites. This includes structural, spatial, and aesthetic aspects.

3. Type of Heritage Sites: The review considers only UNESCO World Heritage Sites within Córdoba, excluding any non-designated or potential heritage sites and the UNESCO intangible cultural heritage of Fiesta of the patios in Cordoba.

4. Document type: Articles, Reviews, Books and Book chapters

5. Language: Only studies published in English or Spanish are included to ensure comprehension and accurate analysis.

6. Publication Type: Peer-reviewed articles, books, and conference papers are included. Non-peer-reviewed articles, opinion pieces, and editorials are excluded.

7. Study Design: While this review is primarily qualitative and descriptive, it includes both qualitative and quantitative studies that provide relevant information.

8. Publication Status: Only published and formally available works are included.

Each researcher independently performed the search on the same day to ensure consistency across the review process. The results from these independent searches were subsequently compared among the four researchers to identify any discrepancies. The extracted data were consistent, with no differences found in numbers or titles. In total, 80 studies were retrieved from SCOPUS, Web of Science, and Dialnet. The data from these databases were exported in RIS format. Using the Rayyan tool (“Rayyan – Intelligent Systematic Review - Rayyan”, 2021), duplicate records were automatically detected. Following this, two researchers reviewed and validated the duplicates identified by the tool and confirmed their removal. After the screening process, 20 records were deleted due to duplication and restricted access, resulting in a final total of 60 studies included in the review. These 60 studies were evaluated to determine their eligibility according to the predefined inclusion and exclusion criteria. No discrepancies were found in the data extracted by the researchers, ensuring the consistency and reliability of the selection process.

Since this review is based on humanities studies and includes descriptive, historical, and qualitative analyses, traditional tools for assessing risk of bias in clinical trials are not appropriate. Many authors have used “trustworthiness”, “validity”, reliability”, “credibility”, “transferability congruence” and “coherence” in their qualitative research (“Quality in Qualitative Evaluation”, n.d.), however the present review proposes a simplified framework based on “trustworthiness”, “relevance” and “coherence” (TRC) to study the risk of bias, as per Annex 2. For instance, the “trustworthiness” component evaluates the credibility and reliability of the study’s findings based on the quality and rigor of its sources and methodology. The “relevance” component assesses the degree to which the study’s findings are pertinent and applicable to the specific research question or objective. Lastly, the “coherence” component measures the logical consistency and clarity of the study’s arguments, including how well the conclusions are supported by the evidence. Each component can be rated as “High,” “Medium,” or “Low” based on the criteria and evidence available. This evaluation helps to provide a clearer understanding of each study’s contribution and reliability and to ensure that the review is informed by high-quality evidence. In this case, two of the authors evaluated the studies separately using the TRC framework, then the other two authors supervised the rating for each study and, in case of discrepancy, a final rate was discussed and proposed between the four authors.

For this systematic review, a qualitative meta-synthesis is conducted to integrate and analyse the findings of the included studies. It provides a holistic understanding of architectural and geometric significance by integrating various perspectives and methodologies while identifying common trends and gaps in the literature. To achieve this synthesis, the selected studies underwent an in-depth analysis, from which key information such as the methodologies used, their limitations, and identified keywords were extracted. Additionally, a risk of bias assessment was performed and included in the meta-synthesis. All of these provide a robust foundation for drawing meaningful conclusions. Each study was further analysed and categorized into one or more of the proposed dimensions.

The categorization process involved the authors independently classifying the studies based on the themes identified in the selected works. This independent categorization ensured diverse perspectives and reduced potential biases. Subsequently, the authors convened to compare their classifications, engaging in a collaborative discussion to synthesize their individual findings into a unified set of dimensions. Through this deliberation, consensus was reached on eight recurring dimensions that best encapsulate the thematic elements across the reviewed literature. These dimensions were recognized as either primary or secondary, depending on their relevance and focus. This categorization allowed for a more nuanced understanding of how different studies contribute to the thematic exploration of this review. It also enabled a comparative analysis of the prevalence of these dimensions and their interrelationships within the literature.

Moreover, the resulting dimensions serve as a flexible and internationally relevant framework for classifying research on UNESCO World Heritage Sites worldwide. By offering a replicable model that transcends the specific case of Córdoba, this framework facilitates comparative studies across diverse cultural and architectural contexts. It empowers researchers and practitioners to systematically explore the architectural significance of heritage sites, thereby enhancing the consistency and depth of heritage research on a global scale. The dimensions are as follows:

1. Evaluation of architectural quality and restoration.

2. Analysis of geometry and architectural patterns.

3. Conservation and architectural changes.

4. Symbolism and recurring themes.

5. Exploration of cultural and social influence.

6. Construction techniques and urbanism.

7. Historical, archaeological and evolutionary perspective.

8. Assessment of heritage and UNESCO criteria.

The results of the synthesis will be presented by comparing the prominence of each dimension and exploring the relationships between them. For example, studies primarily focused on the “Analysis of geometry and architectural patterns” dimension might frequently overlap with studies that explore “Symbolism and recurring themes” or “Exploration of cultural and social influence.” By examining these intersections, the synthesis aims to uncover underlying themes, trends, and gaps in the literature. To visualize the data and understand the relationships between the studies more effectively, VOSviewer (“VOSviewer - Visualizing scientific landscapes”, n.d.) was employed. This bibliometric tool facilitated the visualization of networks of keywords and authors extracted from the studies, allowing for the identification of the most common keywords and the most relevant authors in the field. The extracted figures provide a clearer picture of the thematic clusters that emerges from the literature, as well as the intersections between different dimensions and topics covered by various studies based on the keywords. The combination of rigorous data extraction, risk of bias assessment, dimension-based classification, and visual analysis tools ensures a comprehensive and insightful synthesis that captures the complexity of the architectural and geometric research on Córdoba’s UNESCO World Heritage Sites.

This section provides an analysis of the works (n = 60) selected for this systematic review following the PRISMA guidelines (Abad Castro and González Cavero, 2008; Anderson, 2014; Anderson et al., 2007; Arnold, 2017, 2018; Blanco Guzmán, 2008, 2019; Cabello Montoro, 2017; Capdevila, 2023; Capilla, 2014; Casal García, 2021; Clapés Salmoral, 2020; Cuenca Abellán, 2023; Daza Pardo, 2018; Duran et al., 2008; Escalada Marco Gardoqui, 2017; Escudero Aranda, 2017; Fuess and Hartung, 2014; Galán-Marín et al., 2022; Gámiz Gordo et al., 2022; Gámiz-Gordo et al., 2021; Garrido Anguita et al., 2021; Garzón García and Florido Trujillo, 2019; Gómez-Morón et al., 2021; González Gutiérrez, 2017; Hahn, 2012; Herrero Romero, 2015a, 2015b; Herreros Moya, 2016; Karimi et al., 2020; King, 2018; Lamprakos, 2018; Liñán and Ruiz-Bueno, 2018; López Merino, 2020; Luque Carrillo, 2024; Manzano Pérez de Guzmán et al., 2017; Márquez and Ramírez, 2012; Moya and Menéndez, 2023; Murad et al., 2019; Navascués, 2019; Nickson, 2021; Padilla González, 2023; Ramos, 2005; Redaelli, 2020; Requena-Garcia-Cruz et al., 2023; Riobóo Camacho, 2015, 2016; Roldán-Medina, 2015; Rubio Valverde, 2021; Rueda Olmo, 2016; Ruggles, 2011; Sánchez Álvarez et al., 2021; Sánchez, 2012; Sim, 2022; Suárez et al., 2004, 2005; Utrero Agudo et al., 2023; Vaquerizo Gil, 2020; Villafaina et al., 2020; Wis Molino, 2017). To enhance clarity, the works have been categorized based on their TRC rating, a summary of the methodologies employed, their limitations, authors, keywords, editorial or journal and impact factor. The full dataset of the collected works and their classifications are provided in Annex 3.

The following studies are distinguished by their high TRC ratings as per Annex 3. These were identified as exemplary in their field due to their rigorous methodologies and substantial contributions. The papers include Padilla González (2023), Cuenca Abellán (2023), Gámiz Gordo et al. (2022), Gámiz-Gordo et al. (2021), Garzón García and Florido Trujillo (2019), Cabello Montoro (2017), Riobóo Camacho (2016), Roldán-Medina (2015), Riobóo Camacho (2015), Capilla (2014) and Márquez and Ramírez (2012).

The most recent papers from 2023 to 2022, including works by Gámiz Gordo et al. (2022) and Padilla González (2023), demonstrate a significant shift towards employing advanced digital methodologies. For instance, Gámiz Gordo et al. (2022) utilized 3D laser scanning to create a digital geometric model of the Mosque-Cathedral of Córdoba, comparing it with historical perspectives by Alexandre Laborde. This methodology highlights the trend of integrating digital technologies with historical analysis to achieve precise geometric reconstructions. Similarly, Cuenca Abellán (2023) used comparative analysis to explore symbolic connections, indicating a continued focus on contextual and aesthetic studies. Earlier studies, such as those by Cabello Montoro (2017) and Márquez and Ramírez (2012), reflect a more traditional approach. Cabello Montoro’s examination of urban regeneration and Márquez and Ramírez’s analysis of historical cartography demonstrate the foundational methodologies of archival research and urban analysis, which have paved the way for more technologically sophisticated approaches in recent years.

The methodologies that emerged as most relevant and effective include digital modelling, comparative historical analysis, and detailed geometric analysis. The use of 3D laser scanning and digital models in studies like those by Gámiz Gordo et al. (2022) and Gámiz-Gordo et al. (2021) represents a significant advancement in capturing and analysing architectural details. This approach allows for precise comparisons between historical representations and current architectural models, enhancing the accuracy of historical interpretations. In contrast, studies such as Riobóo Camacho’s (2016) geometric analysis of Madinat al-Zahra and Roldán-Medina's (2015) anthropometric analysis rely on traditional measurement techniques and historical surveys. While effective, these methods are limited by their reliance on historical data and measurement systems that may not fully capture the nuances of architectural changes over time. Despite their high TRC ratings, the studies exhibit common limitations. Many studies, including Padilla González (2023) and Riobóo Camacho (2015), face challenges related to data replicability and historical accuracy. Moreover, some studies, such as Cuenca Abellán (2023) and Capilla (2014), are constrained by their reliance on existing research or a narrow focus on specific artifacts.

To enhance the synthesis of findings from the selected studies, VOSviewer was utilized. Figure 3 presents the visualization of authorship networks, highlighting key contributors and collaborations in this topic.

The analysis identifies Gámiz Gordo as the most influential author, being the first author of two important papers in the present review: “The Mosque-Cathedral of Córdoba: Three Interior Perspectives by Laborde (1812)” and “The Mosque-Cathedral of Córdoba: Graphic Analysis of Interior Perspectives by Girault de Prangey around 1839.” These studies emphasize geometric and architectural analyses, positioning Gámiz Gordo at the center of the field. His scholarly influence extends through his connections with Barrero Ortega and Manzano Pérez de Guzmán, co-authors of “Sobre Arqueología y Arquitectura En Medina Azahara,” and further links to Reinoso Gordo, Salcedo Galera, Ródenas López, Calvo López, and Cantizani Oliva, who are co-authors on his two primary papers. This network underscores a strong collaborative dynamic around key architectural studies, particularly concerning the Mosque-Cathedral and Medina Azahara.

Figure 4 presents an overlay visualization of the keywords, illustrating the largest set of connected terms, comprising a total of 66 items.

The visualization highlights “Córdoba” as the most frequently used keyword, appearing 18 times across the studies (Abad Castro and González Cavero, 2008; Anderson, 2014; Blanco Guzmán, 2008; Gámiz Gordo et al., 2022; Gámiz-Gordo et al., 2021; Garrido Anguita et al., 2021; González Gutiérrez, 2017; Herrero Romero, 2015a, b; Herreros Moya, 2016; King, 2018; Liñán and Ruiz-Bueno, 2018; Luque Carrillo, 2024; Márquez and Ramírez, 2012; Murad et al., 2019; Rueda Olmo, 2016; Sánchez, 2012; Wis Molino, 2017), followed by others such as “Mosque-Cathedral”, “Al-Andalus” or “Islam”. These keywords not only underscore the central themes of geographical and cultural context but also reveal the recurring focus on specific historical and religious elements in the literature. The tool also organises the keywords into clusters that visually represent their relationships and co-occurrence within the studies. As shown, the clusters group related terms such as “architectural proportions”, “geometry” and “plan” in one of the clusters, or “architectural design”, “urban design” and “Al-Andalus” in another cluster. These clusters offer insights into the intersections between different dimensions and topics covered by various studies.

Table 1 shown in Annex 4 presents an evaluation of the selected studies, identifying their primary and secondary dimensions. Each study is categorized under a primary dimension, with secondary dimensions being assigned. Notably, multiple secondary dimensions may be associated with the same study, reflecting the complexity and multifaceted nature of the research. From the data presented, dimension 2 “Analysis of geometry and architectural patterns” emerges as the most common primary dimension, with 13 articles identified under this category. This is followed by dimension 7 “Historical, archaeological, and evolutionary perspective”, which is the primary dimension in 10 studies, and dimension 6 “Construction techniques and urbanism”, serving as the primary dimension in 9 studies. In contrast, when examining the secondary dimensions, dimension 7 appears most frequently, being listed in 32 out of the 60 studies. This highlights its significant relevance across different research contexts. The next most prevalent secondary dimensions are dimension 5 “Exploration of cultural and social influence”, present in 18 studies, and dimension 6 in 17 studies.

Figure 5 illustrates the complex interrelationships between primary and secondary dimensions across the selected studies, providing a nuanced understanding of how different thematic elements are interwoven in the literature. By mapping these connections, the figure reveals which dimensions are most frequently associated with one another, thus highlighting areas of convergence and thematic overlap in the body of work reviewed.

Starting with dimension 1 “Evaluation of architectural quality and restoration”, it shows significant interconnections with dimension 3 “Conservation and architectural changes” and dimension 7 “Historical, archaeological, and evolutionary perspective”, each appearing five times as secondary dimensions. This suggests that studies primarily focused on the evaluation of architectural quality and restoration frequently consider aspects related to both conservation practices and the historical and evolutionary context of architecture. Such a pattern reflects an integrated approach where restoration efforts are closely tied to maintaining historical integrity and addressing conservation challenges.

For dimension 2 “Analysis of geometry and architectural patterns”, there is a particularly strong association with dimension 7 “Historical, archaeological, and evolutionary perspective”, which appears as a secondary dimension in ten of the studies. This relationship indicates that research emphasizing geometric and architectural analysis often situates these patterns within a broader historical or archaeological framework, underscoring the importance of understanding geometrical features not only as aesthetic or structural elements but also in their historical and cultural contexts. Additionally, primary dimension 2 is linked to dimension 1 “Evaluation of architectural quality and restoration” in four studies. Furthermore, it is associated with dimension 3 “Conservation and architectural changes” and Dimension 4 “Symbolism and recurring themes”, each appearing in three studies, indicating a considerable overlap between geometric analysis of architectural patterns and the themes of conservation, architectural changes and symbolic interpretation.

Primary dimension 3 “Conservation and architectural changes” is predominantly associated with dimension 7, appearing in six studies, and dimension 6 “Construction techniques and urbanism”, appearing in four studies. This suggests that conservation practices are often analysed in conjunction with both historical perspectives and contemporary construction techniques. Such a combination points to the dual focus in the literature on maintaining architectural heritage while accommodating modern urban development requirements.

Dimensions 4 “Symbolism and recurring themes” and 8 “Assessment of heritage and UNESCO criteria” show a relatively limited range of associations. For instance, dimension 4 is connected to dimensions 2 and 3 only once, and to dimensions 5 “Exploration of cultural and social influence” and 7 twice. This pattern may indicate that while symbolism is a relevant topic, it tends to be considered more narrowly in conjunction with specific studies that explore cultural influences or historical contexts, rather than being broadly integrated with other architectural dimensions. Similarly, dimension 8 shows associations only with dimension 1 in two instances and dimension 5 in four instances. This limited connectivity may reflect a more specialized focus within the literature on the criteria for heritage assessment and their cultural implications, rather than a broader thematic overlap with other dimensions.

Finally, primary dimensions 5, 6 and 7 are strongly associated with each other. Dimension 5 demonstrates notable interconnections with dimension 6 and dimension 7, each appearing five times as secondary dimensions. This finding suggests a frequent intersection between cultural and social explorations and studies on construction techniques, as well as historical perspectives. This correlation may point to a recognition in the literature of the ways in which cultural contexts and social factors influence both the construction practices and historical development of architectural forms. Regarding dimension 6, there is also a predominant linkage with dimension 7, occurring in four studies, followed by dimensions 1, 3, and 5, each appearing three times. The frequent pairing of construction techniques with historical perspectives reinforces the understanding that contemporary construction methods are often evaluated in light of historical development patterns. Additionally, the connections with conservation, architectural quality, and cultural factors suggest a holistic approach where construction is analysed within broader preservation and social contexts. Similarly, dimension 7 is primarily associated with dimension 6 in five instances and dimension 5 in four instances. The prominence of these connections underscores the centrality of historical and evolutionary perspectives in examining both social influences and modern construction techniques within the selected studies. This indicates a research trend where historical contexts are foundational to understanding both the socio-cultural and technical dimensions of architecture.

Overall, the examination of these primary and secondary dimension relationships provides critical insights into the thematic landscapes within the reviewed literature. The frequent intersections between dimensions highlight key areas of research interest, while the less connected dimensions suggest potential gaps or emerging areas for future exploration. These findings offer a comprehensive understanding of the thematic interdependencies that shape current scholarship in the field.

In this systematic review, a qualitative meta-synthesis was conducted to integrate and analyse the findings from the selected studies. The goal was to identify common trends, gaps in the literature, and offer a consolidated view of existing knowledge that could inform future research and conservation efforts. The review meticulously analysed the methodology, limitations, keywords and risk of bias through the TRC framework of all studies. It also categorized studies into thematic dimensions designed to reflect the focus areas of the included works. This categorization allowed for a nuanced understanding of how different studies contribute to the thematic exploration of this review and facilitated a comparative analysis of the prevalence and interrelationships of these dimensions.

The analysis of the high TRC-rated papers reveals a progression from traditional research methods to advanced digital techniques. The results indicate a significant shift towards the use of advanced digital methodologies in recent years. Studies such as those by Gámiz Gordo et al. (2022) and Padilla González (2023) exemplify this trend, utilizing 3D laser scanning, digital modelling, and comparative historical analysis to provide precise geometric reconstructions and insights into architectural structures like the Mosque-Cathedral of Córdoba. This shift represents a departure from earlier methodologies that relied heavily on traditional archival research and urban analysis. This evolution underscores the importance of integrating modern technologies with historical and contextual analyses to enhance the understanding of Córdoba’s architectural heritage. However, challenges related to data accuracy and methodological replicability remain prevalent in some of the studies (Anderson et al., 2007; Capdevila, 2023; Casal García, 2021; Fuess and Hartung, 2014; Herrero Romero, 2015a, b; Lamprakos, 2018; Liñán and Ruiz-Bueno, 2018; López Merino, 2020; Luque Carrillo, 2024; Navascués, 2019; Nickson, 2021; Padilla González, 2023; Ramos, 2005; Sim, 2022; Utrero Agudo et al., 2023; Villafaina et al., 2020), as shown in Annex 3, highlighting areas for future improvement and innovation in the field.

The visual analysis of keywords shown in Figure 3 underscores the thematic focus on Córdoba, Al-Andalus, and the Mosque-Cathedral, revealing a recurring interest in the architectural and cultural history of these sites. Clustering of keywords reflects the interdisciplinary nature of the research, which intersects fields such as architecture, history, archaeology, and cultural studies. This clustering highlights the interconnectedness of various research dimensions and suggests potential areas for future exploration, such as the integration of social and cultural influences with technical and geometric analyses. In regards of the primary and secondary dimension analysis, it offers critical insights into the thematic landscape of the reviewed literature. “Analysis of geometry and architectural patterns” emerges as the most common primary dimension in 13 studies (Arnold, 2018; Capdevila, 2023; Gámiz Gordo et al., 2022; Gámiz-Gordo et al., 2021; González Gutiérrez, 2017; Hahn, 2012; Karimi et al., 2020; King, 2018; Liñán and Ruiz-Bueno, 2018; Murad et al., 2019; Riobóo Camacho, 2015, 2016; Roldán-Medina, 2015), suggesting a predominant focus on the structural and aesthetic aspects of architectural heritage. This is closely followed by studies with the “Historical, archaeological, and evolutionary perspective” (Abad Castro and González Cavero, 2008; Anderson et al., 2007; Arnold, 2017; Blanco Guzmán, 2008, 2019; Casal García, 2021; Luque Carrillo, 2024; Nickson, 2021; Utrero Agudo et al., 2023; Vaquerizo Gil, 2020) primary dimension and others with the “Construction techniques and urbanism” (Capilla, 2014; Daza Pardo, 2018; Escalada Marco Gardoqui, 2017; Galán-Marín et al., 2022; Márquez and Ramírez, 2012; Ramos, 2005; Requena-Garcia-Cruz et al., 2023; Sánchez Álvarez et al., 2021; Sánchez, 2012) dimension which together underscore the multifaceted nature of architectural studies that encompass both technical and historical analyses. Results show a frequent association between “Analysis of geometry and architectural patterns” and “Historical, archaeological, and evolutionary perspective” which indicates that research in this area often situates geometric and architectural analysis within a broader historical and cultural framework. This trend highlights the importance of understanding architectural features not just as isolated technical elements but as integral parts of historical narratives and cultural contexts.

Moreover, as shown in Figure 5, the connections between primary dimensions such as “Evaluation of architectural quality and restoration” and secondary dimensions like “Conservation and architectural changes” emphasize the integrated approach to restoration efforts, where maintaining historical integrity is closely tied to addressing contemporary conservation challenges. Conversely, dimensions such as “Symbolism and recurring themes” and “Assessment of heritage and UNESCO criteria” show relatively limited connections with other dimensions. This suggests a narrower thematic scope within the literature, focusing on specialized aspects of architectural studies. However, the limited connectivity of these dimensions also points to potential gaps or opportunities for further research. For instance, integrating symbolic interpretations with broader architectural or conservation studies could offer new perspectives on the cultural significance of heritage sites.

The observed thematic interdependencies highlight several key areas for future exploration. The strong focus on digital methodologies suggests a continued trajectory towards more sophisticated technological tools in architectural research. While the increased adoption of 3D laser scanning and digital modelling is evident in recent studies, these technologies have been utilized in Spain for heritage analysis for over a decade. Future studies could benefit from integrating these digital approaches with traditional methodologies to address the limitations identified, such as data replicability and historical accuracy. Moreover, the collaborative nature of authorship networks and the clustering of related keywords indicate a need for more interdisciplinary research that bridges gaps between different thematic areas. Additionally, the limited connectivity of certain dimensions, like “Symbolism and recurring themes,” suggests opportunities for expanding the scope of research to include a more diverse range of perspectives. Future studies could explore the intersection of cultural symbolism with architectural patterns or conservation practices, providing a more holistic understanding of heritage sites' significance.

The study primarily focuses on identifying research gaps in the architectural, geometric, spatial, and urban heritage of Córdoba’s UNESCO World Heritage Site, however, the findings also provide implications for heritage management practices. In particular, Dimension 8 “Assessment of Heritage and UNESCO Criteria” offers a direct connection to UNESCO’s criteria for inscription and its ongoing reporting and monitoring of World Heritage Sites. This dimension highlights areas of architectural and spatial heritage that require more detailed attention in both research and conservation practice, directly supporting UNESCO’s conservation priorities for the site. Further research could explore how these identified gaps can be addressed to better align with UNESCO’s evolving reporting and management strategies for World Heritage Sites. Moreover, to enhance the relevance and applicability of the findings, future research might incorporate feedback from conservationists and heritage management professionals. This collaboration would ensure that academic findings align with actionable priorities at UNESCO World Heritage Sites like Córdoba, ensuring that conservation challenges are addressed in line with current management and preservation goals.

Lastly, the potential to replicate this study’s methodology in other UNESCO sites strengthens the credibility and applicability of the findings, offering an opportunity for broader contributions to the global conservation field. To further consolidate the replicability of these findings, future research should empirically test the proposed framework through case studies in other UNESCO sites. Sites like the Alhambra, the historic centre of Florence or the Medina of Fez could serve as comparative case studies to assess the applicability of the eight dimensions across varied heritage sites. Such an approach would strengthen the generalizability of the findings and contribute to a broader understanding of architectural heritage conservation worldwide.

The present research introduces a novel framework of eight architectural and geometric dimensions, derived from a comprehensive systematic review and meta-analysis of Córdoba’s UNESCO World Heritage Sites. These dimensions, identified from a synthesis of the existing literature, provide a structured approach for understanding the architectural and geometric significance of UNESCO sites, with broad applicability to heritage studies worldwide. This contribution offers valuable insights into how key themes such as architectural quality, geometric patterns, conservation strategies, and cultural symbolism can be integrated into future research and conservation efforts across diverse cultural contexts.

The review identifies key thematic dimensions, such as the “Analysis of Geometry and Architectural Patterns” and the “Historical, Archaeological, and Evolutionary Perspective,” as central to the literature. These dimensions reflect a predominant focus on structural and historical analysis, emphasizing the need to consider architectural features within broader cultural and historical contexts. However, the limited connection between some dimensions, like “Symbolism and Recurring Themes,” presents opportunities for further exploration, suggesting that integrating symbolic interpretations with architectural studies could deepen our understanding of the cultural significance of heritage sites. Moreover, the meta-synthesis highlights a marked shift in recent research toward the integration of advanced digital methodologies, such as 3D modelling and digital reconstructions, which enhance the precision and depth of architectural analysis. While these modern tools offer significant advancements in the study of a heritage sites, challenges remain regarding methodological replicability and data accuracy. These ongoing issues underscore the need for standardized protocols and improved methodological rigor in future research.

On an international scale, the findings of this review have the potential to inform heritage conservation practices and research methodologies across other UNESCO World Heritage Sites. While Córdoba provides a well-documented case study, future research should assess the applicability of these architectural and geometric dimensions in a broader range of UNESCO-listed sites. Expanding this framework to include comparative studies across different geographical and cultural contexts would strengthen its validity and enhance its relevance for global heritage conservation. By addressing existing gaps and embracing advanced technological tools, scholars and practitioners can improve conservation strategies, enrich the understanding of architectural heritage, and contribute to global discourse on the preservation of cultural landmarks. The emphasis on interdisciplinary research and methodological innovation holds broad implications for how architectural heritage is studied and conserved globally, reinforcing the need for collaboration across disciplines and borders.

In conclusion, this research proposes a replicable framework for future research methodologies and conservation practices, contributes to the broader field of heritage studies and offers valuable insights for scholars, conservationists, and policymakers worldwide. Further studies should continue to refine and adapt this framework, ensuring that it remains a relevant and scalable tool for investigating the architectural and geometric characteristics of UNESCO World Heritage Sites in diverse cultural and historical contexts.

The supplementary material for this article can be found online.