The elegant stone Duomo is Sassari's must-see sight. The cathedral, dedicated to St. Nicolas, Santa Claus's inspiration, took more than half a millennium to build: the foundations were laid in the 12th century, and the Spanish colonial–style facade was completed in the 18th. Of particular interest in the interior are the ribbed Gothic vaults, the 14th-century painting of the Madonna del Bosco on the high altar, and the early-19th-century tomb of Placido Benedetto di Savoia, the uncle of united Italy's first king.