Built in the 18th century as Marseille's main hospital, the Hôtel-Dieu occupies a commanding position on the hill above the Vieux-Port. The building is notable for its monumental staircase designed by architect Esprit Brun, a sweeping double-helix that allowed patients and staff to circulate without crossing paths.
The hospital closed in 2006 after more than two centuries of service. Following a careful restoration, it reopened in 2013 as the InterContinental Marseille, but the ground-floor arcades and the staircase remain open to the public. Even if you're not staying, it's worth stepping inside for the architecture and the panoramic views over the old port from the terrace.