The pro-cathedral, set at the highest point of the citadel, was built in the 13th century, badly damaged in a gunpowder explosion in 1567 and rebuilt in Greek-cross plan in the 1620s. The interior is gloomy and atmospheric, with a 15th-century walnut altarpiece, a triptych attributed to Barbagelata, and the Christ des Miracles — a black painted statue carried in procession in 1553 when a Turkish fleet besieged the town and, according to local tradition, withdrew.
Look for the tomb of the local hero Jean-Baptiste de Casanova at the entry and the Cantorum gallery overlooking the nave — a screened area from which noble women followed services without being seen.