2. Literature Review and Conceptual Framework
Heritage tourism is widely understood as a multidimensional form of tourism in which historical, cultural, architectural, symbolic, economic, and experiential dimensions interact. The value of heritage destinations is not limited to the physical presence of monuments or historical sites; it also depends on how residents and visitors interpret authenticity, identity, memory, and cultural meaning. In this sense, perceived authenticity plays a central role in strengthening local identity, cultural resilience, and the value assigned to historical environments (Yi et al., 2024). Similarly, cultural ecosystem services and visitor preferences are increasingly relevant for understanding how architectural heritage can be preserved, interpreted, and used sustainably (Valença Pinto et al., 2024; Moon & An, 2024).
The complexity of heritage tourism also lies in the variety of factors that shape tourism attitudes toward cultural destinations. Historical relevance, aesthetic value, architectural quality, spirituality, environmental conditions, economic opportunities, and managerial capacity all influence how heritage sites are perceived and consumed (Acharjya & Acharjya, 2024). This complexity is consistent with the broader role attributed to cultural heritage in sustainable development agendas, where heritage is not only a tourism resource but also a component of territorial identity, social continuity, and long-term development (Cusumano, 2024). Attributes such as uniqueness, tradition, and cultural continuity remain central to the creation of meaningful tourism experiences (Chakraborty & Ghosal, 2024).
However, heritage tourism does not operate uniformly across space. The distribution of cultural resources, tourism infrastructure, visitor flows, and destination visibility tends to produce territorial differences. Some places become highly consolidated heritage destinations, while others remain underused or less visible despite their cultural value. This territorial unevenness is important because heritage tourism can support urban revitalization, economic resilience, and more responsible forms of tourism development, but these benefits depend on local conditions and management capacity (Nag & Mishra, 2024). Emotional attachment to heritage, including psychological ownership, may also influence preservation attitudes and community engagement, reinforcing the social dimension of heritage tourism (Lin et al., 2024).
From an economic and cultural perspective, heritage tourism has been linked to destination competitiveness, local identity, and the symbolic positioning of territories (Noonan & Rizzo, 2017). Yet, development outcomes cannot be reduced to economic indicators alone. Tourism development is also connected with broader dimensions of quality of life, including education, employment, health, social cohesion, and cultural heritage (Beltramo et al., 2024). This is especially relevant in heritage-rich destinations, where tourism pressure may create tensions between conservation, visitor experience, local life, and long-term sustainability (Matyska, 2024; Navarrete-Hernandez et al., 2024).
A persistent challenge in heritage tourism research is the absence of standardized and comparable frameworks for measuring its territorial performance. Existing indicator systems, such as the European Tourism Indicators System, have contributed to sustainability assessment, but they remain insufficient for capturing the specific complexity of cultural and heritage tourism as a subsector (GSTC, 2019; Kalvet et al., 2020). This limitation is particularly relevant because heritage tourism often overlaps with general tourism flows. Visitors may travel for leisure, business, events, urban experiences, or coastal tourism while simultaneously consuming cultural heritage, making it difficult to isolate heritage tourism through conventional statistics (Richards, 2018; Pedersen, 2002).
The literature therefore points to the need for more heritage-sensitive indicators capable of capturing the interaction between cultural resources, tourist mobility, visitor concentration, and territorial pressure. Policymakers and researchers have emphasized that methodological clarity is still limited regarding which indicators and data sources are most appropriate for evaluating the contribution of heritage tourism to destinations (Pedersen, 2002; Kalvet et al., 2020). This problem becomes even more relevant when comparing territories, since data availability, reliability, and scale vary significantly across destinations (Mohamed et al., 2024).
Heritage inventories are also essential in this process. Far from being merely administrative records, inventories help document built heritage assets, establish preservation priorities, and support evidence-based planning (Soomro, 2024). However, inventories alone do not explain how heritage resources relate to tourism mobility or visitor concentration. For this reason, the measurement of heritage tourism requires integrated approaches that combine heritage concentration, tourism intensity, and mobility data. This need aligns with recent calls for more specialized indicators to guide destination planning, conservation strategies, and long-term competitiveness (Montalto et al., 2019; Zubiaga et al., 2024).
Tourism is inherently spatial. Visitor flows concentrate in some territories and disperse across others depending on accessibility, destination image, infrastructure, attractiveness, and the symbolic value of places. Tourism geography reflects this tension between agglomeration and dispersion: economies of scale tend to attract visitors to consolidated destinations, while the search for authenticity can encourage geographical diffusion toward less saturated areas (Albaladejo et al., 2024). These dynamics are particularly relevant in heritage tourism, where historical environments, cultural landscapes, and architectural assets may create strong territorial attractions.
The increasing availability of geolocation and mobile-phone data has transformed the study of tourism mobility. Traditional observation methods are no longer sufficient to capture large-scale spatial patterns, especially in destinations where visitor flows are complex and dynamic. Geolocation-based techniques provide new opportunities for analyzing long-term mobility behavior, visitor concentration, tourism pressure, and the spatial structure of demand (Padrón-Ávila & Hernández-Martín, 2020; Ruiz-Pérez et al., 2023). Mobile-phone traces allow researchers to examine tourism movements at a scale that was previously difficult to achieve using surveys or accommodation statistics alone (State et al., 2013).
In this context, tourism intensity becomes a useful concept for comparing how strongly tourism activity is expressed across territories. Internal tourism intensity reflects the movement and presence of domestic visitors, while external tourism intensity captures the weight of non-resident visitors. Both dimensions are important because domestic and international tourism do not necessarily follow the same territorial logic. International mobility can act as a structural force behind tourism development and economic policymaking, while domestic mobility may respond more strongly to proximity, accessibility, regional identity, and internal travel patterns (Robin et al., 2022; Choe & Lugosi, 2022). Other mobility studies have shown that tourist density interacts with urban dynamics, residential volatility, and spatial concentration, reinforcing the need to analyze tourism as a territorial phenomenon (Valente & Medina-Ariza, 2024).
Cultural heritage concentration is a central dimension for understanding territorial differences in heritage tourism. Heritage buildings, monuments, historical districts, and culturally significant structures attract visitors not only because of their architectural value, but also because of their symbolic, social, and experiential meanings (Cheung & Wong, 2024). Authenticity continues to influence perceived value in cultural heritage tourism, even if it does not always determine the intensity of immersion or visitor engagement (Liu et al., 2024). This suggests that heritage concentration should be treated as a territorial attribute that contributes to destination differentiation, rather than as a simple count of historical assets.
At the same time, heritage concentration is not evenly distributed. Historical urban development, political investment, conservation policies, cultural recognition, and international designations can create strong differences between territories. Recent studies on the spatial distribution of cultural heritage resources show that heritage assets tend to follow uneven territorial patterns, shaped by historical trajectories and institutional recognition (Zhang et al., 2024). Digital tools, spatial applications, and heritage-oriented technologies have further reinforced the need to analyze cultural resources in relation to their geographical context (Hidalgo-Sánchez et al., 2024; Wang et al., 2024).
The concentration of heritage resources also creates management challenges. High-value heritage environments may attract visitors, but they may also generate pressure on conservation systems, interpretation infrastructure, mobility networks, and local communities (Falk & Hagsten, 2024). Effective heritage management therefore requires diagnostic tools capable of identifying vulnerabilities and guiding conservation strategies, particularly in destinations where architectural heritage is exposed to intensive tourism use (Rusnak et al., 2024). In this sense, heritage concentration should be analyzed together with tourism density and mobility indicators, since the cultural value of a territory and the intensity of its tourism use are not necessarily balanced.
Heritage tourism density provides a useful lens for understanding the relationship between heritage concentration and the population or visitors present in a territory. While tourism intensity captures the magnitude of tourism activity, density helps identify how heritage-related pressure may vary across places. This distinction is important because territories with similar tourism volumes may experience different levels of heritage pressure depending on their cultural assets, resident population, visitor concentration, and spatial configuration.
Sustainable cultural tourism requires the integration of economic, environmental, and sociocultural dimensions (Rawal et al., 2023). In heritage destinations, this means balancing visitor attraction with conservation, interpretation, accessibility, and community well-being. Cultural institutions also need to strengthen communication, interpretation, and visitor engagement strategies in order to improve awareness and support more responsible heritage use (Folgado-Fernández et al., 2024). Festivals, cultural events, and heritage-based activities can intensify the social and cultural functions of historical spaces, but they may also increase pressure on fragile environments if management strategies are not adapted to local conditions (Amer, 2022).
For this reason, heritage tourism density should be understood as part of a broader territorial management problem. It can help identify areas where tourism use is concentrated in relation to heritage resources, as well as territories where cultural potential may be underdeveloped. This perspective supports more differentiated planning approaches, particularly in countries such as Spain, where cultural heritage is widely distributed but tourism demand remains spatially uneven. It also responds to the need for data-driven tools capable of supporting sustainable, evidence-based, and territorially sensitive tourism policies (Egusquiza et al., 2021; Zubiaga et al., 2024).
The literature reviewed shows that heritage tourism is shaped by authenticity, cultural value, mobility, spatial concentration, sustainability, and destination management. However, it also reveals a methodological and empirical gap. Although many studies have examined heritage tourism from cultural, experiential, economic, or sustainability perspectives, fewer have compared heritage tourism indicators across territories using integrated data on mobility, tourism intensity, heritage density, and cultural heritage concentration. This gap is particularly relevant in Spain, where heritage resources and tourism flows are both highly significant but unevenly distributed across provinces.
The present study responds to this gap by framing heritage tourism in Spain as a territorially differentiated phenomenon. The conceptual argument is that heritage tourism should not be analyzed only at the national level, because the spatial distribution of tourism intensity, heritage tourism density, and cultural heritage concentration may vary significantly from one province to another. This perspective does not assume causal relationships among these dimensions; rather, it proposes that their territorial variation is itself a relevant empirical question for understanding heritage tourism planning and management.
Accordingly, this study uses mobile-phone geolocation data, tourism expenditure information, and a heritage concentration index to compare Spain’s 52 provinces. The analysis focuses on four dimensions of territorial differentiation: Internal Tourism Intensity, External Tourism Intensity, Heritage Tourism Density, and Cultural Heritage Concentration. By doing so, the study contributes to the development of a more precise and evidence-based understanding of heritage tourism as a spatially uneven system.