The old town (Città Vecchia) is the heart of the visit: walk from the Castello Aragonese at the southern tip up through the narrow streets to the Cathedral of San Cataldo, with the remains of the Temple of Poseidon standing in Piazza Castello along the way. The Ponte Girevole connecting the old town to the new city is a remarkable piece of engineering still in active use. Across the bridge in the new town, the National Archaeological Museum MArTA contains the finest collection of Magna Graecia goldwork anywhere in the world.