The Museum of Contemporary Art, usually shortened to MAC, gives Marseille a focused look at art from the 1960s onward. It sits away from the Vieux-Port museum cluster, which is part of the point: the visit pulls you into the modern southern side of the city, closer to the beaches, Borély and the road toward the Calanques.
Expect changing exhibitions, French and international contemporary work, and a quieter pace than the big waterfront institutions. It is most rewarding if you already have an appetite for modern art, but it also broadens the Marseille story beyond ships, fortifications and Mediterranean antiquity.