Cagliari climbs from the port to Castello, and Poetto beach lies behind the headland. Stay in the lower centre for train and ferry arrivals, in Castello for the old streets, or at Poetto when swimming matters more than a walk to the sights.
Castello sits high above the harbour. The cathedral, Torre dell'Elefante and the museums of the Cittadella dei Musei reward a stay here, but the steep lanes and steps make luggage hard work. The Bastione di Saint Remy is a landmark between the upper and lower city.
Below the hill, Marina has narrow restaurant streets between Via Roma and the Bastione. Stampace stretches west of Largo Carlo Felice toward the Roman amphitheatre. Piazza Matteotti, the main train station and the ferry terminal are at its lower edge. These areas save a transfer when you arrive from the airport or another Sardinian town.
Villanova lies east of Castello, with Via Garibaldi and Via Sulis leading toward shops and cafés. San Benedetto is farther from the port and more residential. Poetto is a separate beach base east of the centre. Stay there for mornings on the sand and take a bus or taxi to old-town dinners.
July and August bring average highs near 90 °F at Elmas, and autumn has more rainy days. In the warm months, walk Castello early or late and leave the middle of the day for the sea. The centre has limited traffic zones, so ask about car access and parking before you drive to a hotel.