Le Corbusier's Cité Radieuse — officially the Unité d'Habitation de Marseille — was built between 1947 and 1952 in the south of the city, the prototype of every concrete housing block that came after. Le Corbusier set out to design a vertical city: 337 apartments of 23 different types stacked in a single rectangular concrete slab, raised on pilotis, with shops and a hotel on internal "streets," a school on one floor, and the roof given over to a kindergarten, a swimming pool and a sports area.
The building is a UNESCO World Heritage Site since 2016 and is still in everyday use as housing, which gives it a lived-in feel that distinguishes it from a museum exercise. Visitors can wander the open-plan ground floor and the "interior streets" freely; for the roof you need to book a guided tour or stay at the small Hotel Le Corbusier on the third floor. The two-room model apartment on the third floor can also be visited by appointment. Bus 21 from the Castellane metro stops outside; allow an hour to walk around.