Palermo's greatest sights are its Arab-Norman buildings — a UNESCO cluster of monuments that represent the most ambitious cultural synthesis of the medieval Mediterranean. The Cappella Palatina alone justifies the trip. Beyond the monuments, the city's street markets (Ballarò, Capo, Vucciria) are living spectacles, and the Catacombs of the Capuchin monks are among the most extraordinary and unsettling places in Italy.