San Clemente al Laterano

The Basilica of Saint Clement is a Latin Catholic minor basilica dedicated to Pope Clement I located in Rome, Italy. Archaeologically speaking, the structure is a three-tiered complex of buildings: the present basilica built just before the year 1100 during the height of the Middle Ages; beneath the present basilica is a 4th-century basilica that had been converted out of the home of a Roman nobleman, part of which had in the 1st century briefly served as an early church, and the basement of which had in the 2nd century briefly served as a mithraeum; the home of the Roman nobleman had been built on the foundations of republican era villa and warehouse that had been destroyed in the Great Fire of AD 64.

Wikipedia