**5. Discussion**

There is consensus in the culture-focused discourse of the transformative role culture plays in the economic, social and environmental dimensions of development. However, this contribution is yet to be truly visible and tangible in broader sustainability discourses. Cultural sustainability as a concept is still hidden within the agenda of social sustainability and often viewed in tandem. Part of this invisibility is due to the paucity and fragmentation of cultural data and evidence-based research [7,26] that can be used for advocacy of culture in sustainability as well as for integration into development plans and policies at the national and urban levels.

This cross-comparison study of national heritage databases has highlighted that heritage conceptualisations in their broad context are generally aligned with the international framework built by organisations such as UNESCO, ICOMOS and the Council of Europe. However, some differences in approach are reflected in how significance and value is assigned to cultural heritage and what classification is used. The results suggest that certain heritage assets that have significant attached values have been left out of government efforts to raise awareness and promote heritage. There is a larger focus on tangible heritage with historic value and architectural and/or artistic values. This is generally a traditional focus based on the articulation by experts' analysis of heritage. The cross-comparison demonstrates how states are embracing other sociocultural, less visible factors such as the ethnological, anthropological and community values. None of the databases analysed for this paper included the "symbolic" value in their approach as mentioned in the FCS definition, although "cultural" significance is integrated into most of the approaches. The scope of values illustrates the diversity of values used in the heritage conservation management and planning processes, thereby encouraging the widening of the circle of stakeholders involved in value assessment for heritage projects. Consequently, this recognition of multidimensional and interdependent values improves both the process and the outcome. Therefore, based on the results, this paper proposes the integration of a typology of values embracing this diversity in values as a means to facilitate the assessment and integration of different heritage values for the planning and management of tangible and intangible heritage. Multilayered and interdependent values may not be appropriate for all heritage sites and situations. However, it is an attempt to facilitate discussions and understanding of the different valuing processes at play in heritage conservation toward the development of methodological approaches for the SDG indicators, thus bringing new considerations to the discussions about what to conserve, how to conserve it, where to set priorities and how to handle conflicting interests. The working assumption is that these value types encompass most of the heritage values that shape decision making and must be considered within the context of tangible and intangible heritage. The values overlap and are interconnected and therefore should be viewed as different because they correspond to different ways of conceptualising the value of the heritage to different stakeholder groups [29,41].

Indeed, the benefits as discussed earlier from cultural heritage conservation are wide-ranging [29]. The issue of the protection of cultural heritage when considering the contribution to sustainable development is due to the fragmentation and inconsistency of existing national databases, which do not contain some data that are essential. Moreover, they are not standardised, harmonised or coordinated for effective exploitation [59].

Cultural heritage is making a growing contribution to urban economies globally, although a significant limitation is the availability and accessibility of data which varies from country to country. A comprehensive, publicly accessible database on heritage assets for each member state would provide an essential resource to support the SDG monitoring and achievement of the goals. These databases allow for the compilation of heritage in one place, but more importantly, they reflect the classification and valorisation used by the member state. Therefore, the details provided can be used as a comparative tool and data source for analysis. The findings demonstrate broad classification of tangible heritage within the reviewed national databases. These databases are the underpinning for establishing mechanisms for protection. In this regard, databases of local tangible and intangible cultural heritage are critical tools for the management of these resources. They are a key component of cultural management plans and critical in order to know, protect and preserve what is found in a specific area. Documentation and analysis of local knowledge systems, sociocultural practices and values must be documented and analysed as a means to achieve a comprehensive understanding of urban realities.

In the last decade, numerous organisations, meetings and research projects have turned their attention on various aspects related to protecting cultural heritage in Europe and the improvement of methods. Organisations such as ICOMOS (International Council on Monuments and Sites) and ICCROM (International Centre for the Study of Preservation and Restoration of Cultural Property) recommend strengthening the enabling framework for heritage protection through numerous measures, such as the improvement of databases at local, regional, provincial, national and international levels. From as early as the 1980s, the European Commission and the Council of Europe has been supporting documentation on architectural heritage, with the Direction du Patrimoine (France), the Nantes Colloquy on Inventory and documentation methods. Its purpose was to determine practical forms of co-operation between heritage documentation centres throughout Europe and to prepare a definition of common standards on the basis of comparing the inventory methods used in different countries [60]. As part of a funded project by the Getty Conservation Institute, Myers [12] described six characteristics of effective heritage database and management systems. The first characteristic is accuracy; records should have accurate information (such as location and significance/designation status) in order to make decisions and manage risk affecting heritage sites. The second is comprehensiveness; to aim to safeguard all heritage at risk within a particular area, there should be wide-ranging information about the geographic area, as gaps in coverage could significantly increase the risk on heritage. Thirdly, databases need to have up-to-date and current information. The fourth characteristic is authoritativeness; databases and inventory systems should be a definitive system of record for that context. Controlled accessibility is the fifth characteristic, which refers to information from that database that needs to be accessible, such as including data export functionality and expanded search tools. Security of information from corruption or intentional damage is the sixth characteristic. However, spatial content in databases is largely restricted to generalised locational data rather than representing the spatial extents of records.

The sustainability of cultural heritage and its management is strongly dependent on the national, regional and local government and the participation and support from local communities. Involving local communities includes reconciling international and local values of heritage which can sometimes be contested. The involvement of the public in developing the intangible inventories as described in many of the cases reflects the increasing focus on identifying, recognising and valuing the local community as a key actor in the process of sustainable heritage management. Local authorities play a crucial role in enabling this dialogue. Indeed, the local government in many cases, such as in England, acts as a landowner of historic buildings, a facilitator for growth and development and an advocate for heritage. Often set within the context of constrained public finances, the local government must ensure that heritage assets are managed in a sustainable manner in order that the benefits the can be provided be realised.

### **6. Conclusions**

The findings allow concluding that it could be possible to mainstream those indicators across different databases, which could lead to depicting the overall level of attainment of the Agenda 2030 targets on heritage. However, more research is needed to develop a robust correlation between national datasets and international targets. This study confirms the existence of harmonisation of data toward the achievement of the SDGs. The cross-comparison review of the databases identified a broad agreement of the conceptualisation of cultural heritage with international frameworks. The value approaches and classification confirm that states are diversifying in their recognition and documentation of cultural heritage, thereby recognising cultural heritage as an important resource for sustainable urban development, although some inconsistencies still exist when considering the harmonisation of heritage data, such as the use of sociocultural values in assessing heritage and the classification used in identifying tangible heritage. Based on the results from this cross-comparison, the statistical definition of heritage from the UIS UNESCO Framework for Cultural Statistics for the SDG 11.4 target is limiting. It does not fully reflect the conceptualisation that is used across different countries. The current SDG 11.4 indicator is inadequate in representing the challenges and opportunities of cultural heritage within the context of sustainable development. To enhance the comparability of heritage data across cities and countries, there is a crucial requirement for standardised methods for perceiving, valuing, measuring and monitoring heritage. Therefore, national and local capacity development is needed to ensure the sustainability of national and local processes. The harmonisation of these processes using similar

standards and conceptualisation can allow for the comparison of data among countries toward the achievement of the SDGs.

A limitation of the methods used in this paper is that this can only be considered as a "snapshot", as the databases are constantly updated and changed. Therefore, not all information will be available publicly, and this is not a complete reflection of the processes and information that are available. The authors selected a small sample of countries in the European region intended to illustrate the level of harmonisation. It is important to highlight the contextualisation of these areas and the differences that exist between the countries in this region. This could not be covered sufficiently in this paper. Furthermore, this paper did not use national statistics data for culture in its entirety due to the lack of comparable data, particularly qualitative data, for multiple European countries. However, this cross-comparison acts as an indication of the gaps and possible harmonisation that exists within European cultural heritage practices and processes.

Future research is recommended into the pluralistic values and impact of cultural heritage in achieving sustainable development. There are many emerging studies and projects that present various aspects of the vital role of heritage and the development of heritage indicators. However, many of these are concerned with only selected aspects of the potential impact of cultural heritage and tend to lack evidence. Future research development can therefore include the development of evidence-based indicators for European countries with emphasis on highlighting the multifaceted role of cultural heritage in sustainable development. This paper also acknowledges that future findings from heritage-related research projects such as those funded through the current Horizon 2020 research programme [60] will fill gaps of knowledge. The continuous development of cultural data and the international efforts towards data interoperability open up possibilities for new research and unique comparisons of the impact of culture between European countries. In conclusion, the evaluation of cultural heritage at multi-levels to the achievement of sustainable development as emerging from the analysis requires the recognition that the benefits from cultural heritage conservation are multivalent, pluralistic and layered from state to state, thus calling for national, regional and local government and heritage stakeholders to carefully integrate of these aspects into the development of multidimensional SDG indicators.

**Author Contributions:** Conceptualisation, L.P., C.T. and B.N.M.; Methodology, L.P., C.T. and B.N.M.; Supervision, L.P.; Writing—original draft, B.N.M.; Writing—review and editing, C.T. and B.N.M. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research is financed by the PRIN program—Research Projects of National Interest, Italian Ministry for University and Research, n. 2015EAM9S5, Project name "Protecting the Cultural Heritage from water-soil interaction related threats".

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
