This imposing 12th-century Romanesque structure was built on the site of Roman baths and an early Christian basilica. Inside, note the rare early Christian carving of two birds eating a fish on the first column next to the apse. The left nave features a Gothic chapel from the 15th century, with the coats of arms of the Frankopan princes who used it as a place of worship. Grafted onto the side is an 18th-century campanile with onion dome and angel statue.
Next door, the adjoining St Quirinus' Church is another Romanesque church built of white stone and dedicated to the island's patron saint. Among the art and vestments stored in its treasury is a silver altarpiece depicting the Madonna that dates to 1477.
