Basilica di San Clemente

A stately church that holds its own in a city packed with places of worship, the Basilica di San Clemente holds layers of surprises beneath its marble floors.

Below this "modern" 1120 church is the original basilica, which dates back to 392 AD. This original, known as the "first basilica" was rediscovered in the 1860s during excavations. This long-sealed first basilica holds the world's second largest collection of early Medieval wall paintings.

One layer further into the earth are the remnants of a first century Roman villa that served as both an early site of clandestine Christian worship that also contains a Mithraic temple and a babbling stream.

Update July, 2017: Restoration work  is obscuring a good portion of the modern basilica's interior.