San Clemente is a beautifully frescoed twelfth century historic basilica in Rome. However, whilst interesting in its own right, it is what lies underneath San Clemente which is a highlight to historians.

In the mid-nineteenth century, when San Clemente was excavated, it was discovered to have been built over both a fourth century church and a third century Temple of Mithras.

The former site is extremely well preserved and lined with faded frescos, whilst only one of the rooms of the Ancient Roman Temple of Mithras remains. There are also ruins of some Roman houses.

Visitors can descend under San Clemente to view these sites.