3D digital technologies for architectural analysis. The case of the "Pagan Shrine" in the Catacombs of Santa Lucia (Siracusa, Sicily)

The Catacombs of Santa Lucia are one of the oldest and most important monuments in the Christian communities of Siracusa and Sicily in the late Roman period. The name of the complex derives from a tradition, according to which Saint Lucy was buried here, after her martyrdom in the early 4th century AD, under the reign of Diocletian. A large underground cemetery extends beneath the homonymous square. The cemetery gradually expanded from the 3rd to the 5th century AD, as it incorporated pre-existing constructions once used for funerary, religious and industrial purposes, by transforming them into monumental burial chambers. One of the most significant structures is the so-called ‘Pagan Shrine’: a chamber that is dated between the 3rd century BC and 1st century AD, prior to the foundation of the cemetery and frescoed with worldly themes and pagan deities. The Shrine is located in the South-western corner of Regio C, an area that is hard and rather dangerous to reach, never opened to the public and visited only by few scholars over the past decades. The excavation project undertaken in the years 2011-2015 by the Pontifical Commission of Sacred Archaeology, in association with the Arcadia University and the University of Catania, led to the development of the first virtual replica of the Shrine, using Digital Photogrammetry. This new approach facilitated an accurate examination of both its structure and its decoration, allowing us to propose a new theory about the original purpose of the room, traditionally regarded by scholars as a place for worshipping Zeus Peloros.