located in the Catacomb of Priscilla, a remnant from a large Roman villa. The U.S. Embassy in Rome has a great webpage about The Cryptoporticus. Apparently while they were building the embassy, they stumbled upon one. It has a lot of information and great resources/references. Here's the link. https://it.usembassy.gov/embassy-consulates/rome/cryptoporticus/ References External links A picture of a cryptoporticus at Hadrian's Villa at Tivoli in Italy A cryptoporticus at Chateau d'Anet in Anet, Eure-et-Loir, France The cryptoporticus of Arles Ancient Roman architecture Rooms Semi-subterranean structures