1 Best Sight in Boulder and North Central Colorado, Colorado

Hot Sulphur Springs Resort and Spa

At Hot Sulphur Springs Resort and Spa, 15 open-air pools are sprinkled up the hillside, with temperatures ranging from 98°F to 112°F, and a day pass grants access to all of them. The seasonal swimming pool is just right for recreation, at a comparatively frigid 80°F, and the resort also has four private, indoor pools (two reserved for spa treatments). Bring sandals if you have them, especially during snowy months when rock salt is used on icy walkways.