The citadel sits on a rock spur jutting into the bay, ringed by enormous walls and a glacis. Inside, the streets are narrow and the buildings tall, the colour of pale honey. The Genoese built it from the 13th century onwards as a forward base in the western Mediterranean; the seaward bastions still carry old cannon embrasures.
It is best entered through the main gate and explored on foot, climbing through the ramparts to the high terrace for views over the marina, the long beach and, on clear days, the snowy interior peaks. The 2nd Foreign Parachute Regiment is garrisoned in the modern wing of the citadel — you may see legionnaires in mess kit in town.