Marseille’s uber-cool option, the five-star C2 was launched in 2014. Twenty luxurious, light-filled rooms spill over a 19th-century merchant family mansion typical of this portside quarter, each one decked out in exposed brick walls and designer furnishings. Some have a private hammam steam bath. The superb Filorga Spa onsite has an indoor pool and Jacuzzi, as well as a cocktail bar. But the hotel’s pièce de résistance? That would have to be C2's beach on the private Mediterranean island of Île Degaby. Pack a picnic and castaway.