Fort Saint-Jean is a fortification in Marseille, built in 1660 by Louis XIV at the entrance to the Old Port. Since 2013 it has been linked by two foot-bridges to the historical district Le Panier and to the Museum of European and Mediterranean Civilisations; the latter being the first French national museum to be located outside Paris.

More details: https://en.wikipedia.org/wiki/Fort_Saint-Jean_(Marseille)