Mentioned in a parchment of 1087, according to the historians it could date back to early Christian times. It was altered in the sixteenth century and in baroque times. The plan is in the shape of a Latin cross. The façade retains some of its original features, such as the portal, the double lancet window and two friezes, maybe Roman; in baroque times, two small canopy-shaped gables enlivened its original square appearance. On the left side of the church are two richly-decorated doors, one of which has a Roman lintel dating from the I-II century AD, in Hadrian’s time, on top. Slightly jutting out is the apsidiole, decorated with thin pillars and hanging arches. Inside one can see eight columns made of pieces of marble and stone ashlars, holding some rough-hewn capitals, abaci and round arches; one of the eight columns has, under the necking, a frieze with rich festoons. Resting against the entrance wall are two half-columns, one of the Servian age (III century AD.) on the left, the other of the Trajan-Hadrian’s age (II century AD). The vault was remade in the sixteenth century, like the central hemispherical dome. Original are instead the barrel vault of the right arm of the transept and the cross vault of the vestry, supported by squat pillars.