Low-accessible Cultural Heritage, including hypogeal sites, rupestrian architectures, and fragile structures, represents a major challenge for conservation, documentation, and continuous monitoring. These limitations stem from multiple inaccessibility factors, classified as physical (morphological complexity), asset risk (microclimatic instability), health and safety (structural vulnerability), managerial (lack of public access), and cognitive (lack of documentation). This research aims to transform digital models from mere representational tools into integrated cognitive and operational systems supporting decision-making and preventive conservation. The proposed methodological workflow is structured into five main phases: Preliminary Knowledge and Multidisciplinary Data Structuring (Ph1. PK–MDS), Comprehensive Digital Survey (Ph2. CDS), Development of Integrated Digital Models (Ph3. IDMs), Advanced Diagnosis and Monitoring (Ph4. ADM) and the implementation of an Integrated Digital Environment for Hypogeal Heritage Management (Ph5. IDE). Ph4 operates on two complementary scales: at the site scale, range-based point clouds enable the semi-automatic identification of extensive decay patterns, such as biological colonization. At the detail scale, the Random Forest algorithm enables the segmentation and quantification of material loss on frescoed surfaces through a diachronic comparison of historical and current data. Validated on the San Pellegrino complex in Matera, selected as a paradigmatic case study of low-accessibility hypogeal sites, representative of a broader system comprising approximately 150 rupestrian cult architectures, the methodology demonstrates how immersive digital environments function as shared knowledge spaces, supporting more informed, inclusive, and resilient heritage conservative management.

Hypogeal environments constitute a significant yet often understudied component of cultural heritage, encompassing a wide range of underground spaces such as caves, quarries, cisterns, catacombs, and hypogeal settlements. These environments are characterized by complex spatial configurations, stratified historical transformations, and challenging accessibility conditions, which frequently hinder systematic documentation and management. Traditional cataloguing approaches, often based on descriptive inventories or isolated surveys, struggle to adequately represent the spatial, functional, and material complexity of underground heritage. In recent years, the growing availability of data management systems has opened new opportunities for the development of structured and interoperable cataloguing procedures. This research proposes a digital workflow aimed at supporting the structured cataloguing of hypogeal environments through the integration of digital procedures, semantic information, and heritage documentation standards. The methodological approach integrates participatory practices, semantic modelling, and digital data management tools within a single operational workflow. The information acquisition process is based on a collaborative data collection system that involves both non-expert users, such as the owners of hypogeal sites, and domain specialists. The participatory contribution is guided by a formalized information structure, defined through a survey record designed according to a logical–conceptual model that integrates principles of information system modelling with consolidated ontological structures adopted in the cultural heritage domain. In parallel, the adoption of an automated digital pipeline, based on shared sheets, integration within an information system and a GIS environment, and the automatic generation of cataloguing records, enables the creation of a coherent and replicable data management workflow. The methodology is applied to the cataloguing of the hypogeal wine cellars of Utiel (Spain), demonstrating the effectiveness of the proposed workflow in a real case study and highlighting the potential of digital procedures to improve the documentation and knowledge of underground heritage.