Non-invasive investigation and digital reconstruction of a small catacomb complex in Rabat (Malta)

Abstract

This study presents the results of a Ground Penetrating Radar (GPR) investigation combined with a photogrammetric survey of a small archaeological site in Rabat, Malta. The investigation was conducted in preparation for small but challenging road infrastructure works in view of the surrounding archaeologically rich landscape. This area is characterized by a significant concentration of Punico-Roman tombs and more extensive hypogea datable to the Late Roman and Byzantine periods. GPR survey shows anomalies in the form of elongated patterns, some of which aligned to a number of blocked entrances discovered during an archaeological investigation of the site carried out prior to the GPR survey. These anomalies are being interpreted as underground passages, known as ambulacra, of a previously undocumented Late Roman hypogeum. The newly discovered underground passages were mapped out in the obtained 3D photogrammetric model and orthophoto. Both results were plotted and analyzed together in 2D and 3D environments.