The Church of St Peter is very ancient and was attached to the ducal palace near the castle gate. In 1702 it was totally destroyed by an earthquake and in 1750 it was rebuilt larger by Gerolamo Pamphili.
Inside it has a single nave covered by a barrel vault and has two chapels on each side. To the right of the main altar is a ciborium, a canopied altar, attributed to the school of Mino da Fiesole.
In a chapel is an oil painting in a neoclassical style that represents the “Madonna del Soccorso” painted by Vincenzo Camuccini.
The current organ dates from 1930 and under the floor of the church are the remains of ancient tombs as was the custom before the implementation of cemeteries.