Fodor's Expert Review Les Thermes Marins de Monte-Carlo

Added to the city in the 1990s, this seawater-therapy treatment center stretches between the landmark Hôtel de Paris and its sister, the Hermitage, and can be accessed directly from either hotel. Within its sleek, multilevel complex you can pursue every creature comfort, from underwater massage and seaweed body wraps to a 50-minute Monte-Carlo Foot Cocooning Massage (€160) in one of the 37 treatment rooms—almost all with views over the port. This is also the only spot in Europe offering crotherapy, a treatment where you spend a couple of minutes in two cold chambers at -60°C and then -110°C, and is said to help with jet lag, sleep disorders, and anti-aging. You'll definitely want to indulge in the outdoor hot tub afterward and enjoy an elegant spa lunch at L'Hirondelle as you thaw.