Les Thermes Marins de Monte-Carlo

Perched on a cliff overlooking the Mediterranean, this enormous high-concept palace of pink marble, wood and glass is one of the principality’s star attractions. After a massive facelift, the spa offers both thalassotherapy and a wide selection of high-tech beauty and well-being treatments, plus a heated indoor seawater pool, a hammam, a sauna and a state-of-the-art fitness center. Among the latest cutting-edge highlights is the Miha Body Tech, a treatment that tones and strengthens through electro-stimulation. There is also the extravagant Monte-Carlo Diamond treatment, a massage and scrub with genuine diamond powder and essential rose oils; the Tonic Minceur treatment, with detox algae wraps; and the six-day “for men only” program, with everything from cardio training to anti-aging facials using La Prairie products. The numerous day spa options range from seaweed wraps and Dead Sea mud packs to diverse massage techniques, including Shiatsu and fasciatherapy a deep kneading that keeps guests energized for weeks. If you’re staying at either the Hôtel de Paris or the Hôtel Hermitage, you have free access to the pool and the lovely solarium terrace overlooking the harbor.