4. Hot Springs State Park, Wyo.
In 1896, the Shoshone people sold the land that is now Wyoming's Hot Springs State Park to the federal government. One of Chief Washakie's conditions was that the soothing waters be forever free of charge, making this a rare no-cost opportunity to enjoy a natural spa treatment. The public park has indoor and outdoor bathing pools, though soak time is limited to 20 minutes a person every two hours. While waiting for your next session, you can walk over the Bighorn River on a suspension bridge and stroll among the hot-spring terraces. For an affordable spa and resort-like experience, check into the Thermopolis Days Inn. It's not your typical no-frills roadside motel: This Days Inn is within the park and has pools and saunas fed by local hot springs. Weekend packages start at about $220 for two nights for two people. The Fountain of Youth RV Park has three of its own thermal pools — and rates of $33 for two people per RV.
5. Heartland Spa, Ill.
The Heartland Spa offers all-inclusive and affordable spa getaways in Gilman, about 90 miles south of Chicago. Set on 32 acres of former dairy farmland and accommodating only 32 guests, the Heartland is a low-key countryside retreat. This is the classic destination spa experience, with three spa cuisine meals a day and a packed roster of exercise classes, motivational speakers and workshops throughout the year. To really get into the Heartland spirit, a stay here gets you comfy workout clothes — sweats, shirts and shorts — to wear while on retreat. The full spa menu offers massage and energy work, as well as nutrition and diet counseling. A two-night stay starts at $670 per person in a double, including spa credits.
For more ideas, visit Spafinder.com, which lists destination and day spas around the world.
Also of interest: Culinary tours: adventures in food tourism.