Naples, a city in southern Italy, sits on the Bay of Naples. Nearby is Mount Vesuvius, the still-active volcano that destroyed nearby Roman town Pompeii. Dating to the 2nd millennium B.C., Naples has centuries of important art and architecture. The city's cathedral, the Duomo di San Gennaro, is filled with frescoes. Other major landmarks include the lavish Royal Palace and Castel Nuovo, a 13th-century castle.