In the Flavian or Trajanic period, a bathhouse was constructed where the S. Pietro a Corte now stands. Inscriptions dating from the fifth to the eighth century indicate that the frigidarium was reused in this period as a Christian place of worship and burial. The eighth-century Longobardian duke of Benevento Arechis II had the vaults of the bathhouse destroyed, but reused the large pylons of the frigidarium as the foundations for the reception hall and chapel which he built on top of them, and which form the core of the current church. The frescoes currently visible in the frigidarium date to the 12th century.
The remains of the bathhouse can be visited for free via a side entrance. The church itself can be visited as part of a reserved but free guided tour.