Terme di Saturnia, Italy
Terme di Saturnia is in Tuscany, Italy — a region often associated with wine tourism. But this visually impressive geothermal spring, a couple miles outside of its namesake town, also draws plenty of tourists. The water pours over the falls at 99.5 degrees Fahrenheit. It is rich in minerals like calcium and magnesium and in sulfurs. This combination is supposedly good for the cardiovascular and respiratory systems as well as for skin.
A luxury spa and hotel, complete with golf course and Michelin-starred restaurant, is located near the spring. In addition to offering a chance to soak in the water, the spa has a range of wellness treatments.