The construction of this military complex dates back to the 17C, when Louis XIV decided to reinforce the city's defences. Take a walk around the interconnected vaulted rooms, inner alleyways and rampart walks, which offer fine views. Fort St-Jean is now an integral part of the Mucem. Adjoining the fort is a former blockhouse, now home to the Mémorial des Déportations. Dedicated to the victims of Nazi barbarity, this museum tells the story of the round-up of Marseille's Jews on 22 January 1943.