This atmospheric church is the main attraction on the tiny Isola San Giulio and was built over various periods dating back to the 9th century. Its bell tower and medieval pulpit date from the 12th century. Frescoes (from the 14th to 19th centuries) cover the walls, though the church's most surprising feature is in the sacristy. From the vault hangs a large fossilised vertebra, which according to legend belonged to one of the terrible dragons San Giulio vanquished from the island.