Barton Springs Pool is often crowded year-round, as the temperature rarely drops below 68 degrees, but that's no problem, as this spring fed swimming hole is over 900 feet long. Easily a favorite destination among Austin locals, and a must-visit for summertime visitors to Austin.
A tiny, unincorporated community in Taos county, the town of Ojo Caliente more or less is its hot mineral springs. The luxury resort (the eponymous Ojo Caliente Mineral Springs Resort & Spa) here has a long history, stretching back to 1868, of revitalizing and rejuvenating visitors.
Why not break up your adventure through wine country with a little visit to the "Old Faithful of California?" Californians–Calistogans in particular–are proud of their Little Old Faithful. The town also has a number of spas that derive (either through inspiration or in actuality) from the springs. The spas of Calistoga are renowned for their local twist on mud baths: a total immersion in hot volcanic ash. It sounds terrifying, but it's utterly invigorating.
The underground vapor steam baths of Glenwood Springs–known as the Yampah Hot Springs–were once used by the Ute Indians, and were a primary reason that this settlement took root in the first place. Today, there is an adjoining spa, salon, and lodge that's a popular attraction for locals as well as visitors.
One of Iceland's most-visited attractions, the Blue Lagoon is a geothermal spa located in a lava field. The mineral rich water is renowned for its revitalizing properties, and an adjoining research facility is perpetually searching for new ways to put the minerals to use in curing skin conditions.
Fanning Springs State Park is all about 'what nature put there.' If you like to swim in crystal clear water, in a beautiful natural setting, set your GPS for Fanning Springs State Park. Located in north central Florida, it's equidistant to both Jacksonville and Orlando.
Strawberry Springs Park near Steamboat Springs, CO
Drive out to Strawberry Springs Park for a swim on a Colorado summer day and you're never look at swimming pools the same way again. Stick around for a nighttime soak and things get far more interesting. Last time we checked, this was a clothing-optional pool (and a 'locals favorite' place to chill).