For thermal bath enthusiasts, Colorado has an 800-mile itinerary that links the state's historic hot springs ... indoor pools and seven outdoor hot springs free from the crowds.

Napa Valley's historic Indian Springs Calistoga dates ... where foliage and fencing create some privacy. Wild Willy's Hot Springs is a free, easily accessible and scenic spot to soak about a ...

As the headquarters of Yellowstone National Park, the Mammoth Springs Historic ... Hot Springs has no set hours and access is covered by Yellowstone's seven-day admission fee ($35 per vehicle ...

It bubbles up above the ground in the form of hot springs across the country ... There are dozens of free spots for a swim across Italy. Some, like the spectacular natural terraces of Saturnia ...