This paper focuses on a research project for the acquisition and post-production of digital data to create informative virtual representations and digital twins of different European Cultural Heritage sites. The goal was to establish a reliable database for a multi-scalar web platform, also accessible through extended reality (XR) tools. This initiative aims to support the promotion and management of cultural and historical monuments within the context of European Cultural Routes supported by the Council of Europe. The project involves different case studies spanning European geographic regions, such as the Upper Kama in Russia, the Valencian Routes of Jaime I in Spain, and the Gdańsk fortresses in Poland. The methodology employed in this effort primarily relies on integrated rapid survey techniques. Unmanned aerial vehicles (UAVs) and simultaneous localization and mapping (SLAM) technologies were used for data collection. These methods contribute to the creation of accurate 3D databases and models that transform the cultural routes into a digital format accessible via an informative platform. The actions presented in this paper are part of the European project “PROMETHEUS”, which is funded by the Horizon 2020 program of the European Union. The project involves collaboration between universities and enterprises, fostering inter-sectoral cooperation. Various techniques such as photographic archives, census analysis, and scan-to-BIM (building information modeling) processes are employed to develop this method further. In fact, the ultimate goal of the project is to establish a framework that can be replicated in other cultural contexts, enhancing the digital documentation and valorization of heritage sites.

The will to preserve and enhance cultural heritage imposes reflections on databases as containers of information for the accessibility of dispersed heritage. The aim of the research is to validate methodological approaches in order to create 3D models and information systems. These tools improve accessibility to the artifact, according to different interconnection channels, in order to overcome the physical limit imposed by location. Tangible and intangible heritage take the form of a metadata network throughout a critical analysis and elaboration of data. These files create a complex database containing 3D models rich in information that describe cultural systems. The digital survey is the starting point for the development of languages, signs and symbols. It transfers complex objects into virtual systems, developing a multidimensional dialogue capable of integrating actions and meanings. The interactivity of complex databases facilitates the accessibility and disclosure of data to a wide audience. It requires the establishment of representation systems based on the development of virtual environments.

The present paper illustrates the documentation activities developed since 2013 on Upper Kama territories, preliminary to an extensive and joint research action within the European project “PROMETHEUS” (2019–2021), which aims to produce digitized databases and models for the management of the main religious monuments present on this Russian area, nowadays endangered by risk of conservation. The project is funded by the EU program Horizon 2020 – R&I – RISE – Research & Innovation Staff Exchange Marie Skłodowska-Curie, and it is aimed at the definition of inter-sectoral collaboration protocols for the development and promotion of a new methodology for the development of reliable 3D databases and models of monumental complexes in Upper Kama region. The project, that involves the collaboration between three Universities (University of Pavia, Italy, Polytechnic University of Valencia, Spain, Perm National Research Polytechnic University, Russia) and two enterprises (EBIME, Spain, SISMA, Italy), aims to promote actions to develop interdisciplinary activities for the documentation, management and production of collaborative H-BIM models, for the start-up of monitoring and development activities on this specific Cultural Heritage. Researches and initiatives conducted in the previous years on Upper Kama territory highlight potentialities and opportunities of digital survey to define a basis of knowledge that is both scientific and technical, for future interventions on endangered architectural heritage, where academies, companies and administrations promote actions to develop interdisciplinary documentation activities through collaborative management H-BIM models and an intervention protocol on Cultural Heritage.

The present paper illustrates a part of the methodological process of image-based acquisition developed for the documentation of the historical city center of Bethlehem, in the Middle East territory. The first mission of research activities, developed inside the international cooperation project “Management and control of urban growth for the development of heritage and improvement of life in the city of Bethlehem” (2018–2021), coordinated by University of Pavia in collaboration with the Municipality of Pavia and financed with the contribution of AICS (Italian Agency for Cooperation and Development), has been carried on through combined application of digital instruments, TLS and UAV, with the aim of developing “smart”, low-cost and rapid execution procedures for the production of a reliable three-dimensional model of the historic city center. The paper shows the application of different photogrammetric survey campaigns in a portion of the historical town, acquisition problems and tests of morphometrical reliability of each output, in order to develop a general SfM database consisting of different definition levels of the photogrammetric models of historical city center.

The paper explores two fortified systems, as case studies, to evaluate different modelling approaches, the parameterisation of architectural components, and semantic interpretation, to define a repeatable methodology for classifying, accessing, and sharing architectural information. The use of informational structures to categorise data and relations through semantic attributes addresses the need to make data queryable and interoperable. In architectural documentation, this practice opens up new perspectives for creating and sharing collaborative repositories, radically transforming the way of disseminating and accessing knowledge. Linking qualitative data information with 3D models enables the development of semantic structures that provide a deeper understanding of intrinsic characteristics, historical transformations of architectural complexes, and their cultural context. While databases effectively manage structured information and relationships between different signifiers, semantically enriched 3D modelling, through the management of surfaces or parameters, offers an accurate and flexible representation of each component. The evaluation of these case studies not only improves the ability to understand and appreciate built heritage but also provides new opportunities for researchers in architectural documentation and history. Semantic subdivision processes of built complexes into individual components facilitate the analysis and the digital preservation of heritage, enabling more precise interpretations and faithful reconstructions.

Cultural heritage and the attendant variety of built heritage demands a scientific approach from European committees: one related to the difficulties in its protection and management. This is primarily due to the lack of emergency protocols related to the structural knowledge and documentation pertaining to architecture and its ruins, specifically in terms of the goals of protection and intervention for endangered heritage affected by mechanical instabilities. Here, we focus on a rapid and reliable structural documentation pipeline for application to historical built heritage, and we introduce a case study of the Church of the Annunciation in Pokcha, Russia, while we also review the incorporation of integrated 3D survey products into reality-based models. This practice increases the possibility of systematising data through methodological phases and controlling the quality of numerical components into 3D polygonal meshes, with millimetric levels of detail and triangulation through the integration of terrestrial laser scanner and unmanned aerial vehicle survey data. These models are aimed at emphasising morphological qualities related to structural behaviour, thus highlighting areas of deformation and instability of the architectural system for analysis via computational platforms in view of obtaining information related to tensional behaviour and emergency risks.