Some two millenniums after the Romans built their stony thermal baths at Aix, self-styled Caesars are still luxuriating in the therapeutic waters shot up from underground springs. These days the pampering unfolds at Thermes Sextius, a vast modern spa built atop the old baths (still visible through glass panels in the lobby). Treatments vary from hot stone therapy to warm mud wraps, but the hydrotherapy cabins and tubs are the real draw. The Modelage Zen treatment directs five jets to spray on your back, as you receive an almond oil massage.