Geoheritage and Cultural Heritage Interface in a Place of Worship: The Historical Development of the Monumental Complex of San Francesco le Moniche in Aversa (Italy) and Its Underground Artificial Cavities

The case study of the monumental complex of San Francesco le Moniche, built in the ancient Norman county Aversa, in northern Campania (Italy), is analyzed here. The cultural heritage of the complex and the additional value associated with geoheritage (building stones and underground extraction cavities) have been highlighted. The building stratification of the complex was reconstructed based on documentary sources, including historical cartography and photographic documentation of postcards from the early 1900s. It began around 1200 and ended in the 20th century; part of the original citadel was dismantled and incorporated into the urban fabric in the Fascist era. The building stratification of the complex was also read from the distribution and architecture of the existing underground cavities from which the building stones were extracted. The subsoil, reconstructed on the basis of geological and geophysical data, is made up of a tuff substrate, starting from approximately 5–6 m from the ground level, which represents the main building stone as well as being an important testimony to the long volcanological history of northern Campania. Laser scanner surveys of the known and accessible cavities were carried out to obtain a three-dimensional view of the entire monumental complex and its underground spaces. The results provide a clear example of a geoheritage–cultural heritage interface which reminds us of the importance of an integrated approach in their valorization, specifically in urban areas. Additionally, the results of the study allowed us to improve the knowledge of the complex and the site, and provide useful tools for the planning of future targeted investigations.