The Basilica of Sant Angelo in Formis is an eleventh century Benedictine church constructed on the former site of a Roman temple dedicated to Diana Tifatina. In fact, the remains of this Roman temple are incorporated into the Basilica of Sant Angelo in Formis, including its Doric columns and floor, both of which were once part of the temple.

The current form of Sant Angelo in Formis dates back to 1053 when it was built by the Abbot of Montecassino Desiderius, who was later Pope Victor III. Visitors to Sant Angelo in Formis can view its colourfully frescoed interior.