Spas with thermal pool

Palm Springs, California

A 16-room adults-only hotel in Desert Hot Springs with three natural mineral-water pools fed by a 350-foot geothermal well, plus a small on-site spa and

Rogaška Slatina, Savinjska

Wellness center at Grand Hotel Rogaška in Rogaška Slatina, Slovenia, with pools, saunas and fitness; day pass available by reservation.

Gold Coast, Queensland

A 90-minute hydrotherapy circuit in Southport with a Finnish rock sauna, 5° ice baths and hot/cold magnesium pools, day pass $49.

Rotorua, Bay of Plenty

A Rotorua day spa built around Ngāti Whakaue hot-springs traditions, centered on a seven-step geothermal Restorative Journey with lakeview thermal pools, mud

Taupo, Waikato

Adults-only geothermal hot springs in the Wairakei valley near Taupo, with three thermal pools fed by natural silica-rich mineral water, plus spa treatments

Carmel, Indiana

A moderate-priced day spa in Carmel, Indiana with sauna, steam room and thermal pool, plus facials, massage and body contouring treatments.

The Colony, Texas

A day-soaking spa in The Colony with mineral pools at varying temperatures, seven saunas, cold plunges and a poolside café.

Glenwood Springs, Colorado

A natural geothermal vapor cave in Glenwood Springs, Colorado, where visitors steam in ancient rock chambers and add massages, mineral baths or body treatments.

Noboribetsu, Hokkaido

A plain neighborhood bathhouse in Noboribetsu, Hokkaido, offering 100% source-fed hot spring water in two mineral varieties, about 10 minutes from the station.

Soufrière

Hotel spa at Ladera on the Pitons ridge in Soufrière, with day passes, couples treatments and volcanic mineral pool access.

Palm Springs, California

Adults-only clothing-optional resort in Desert Hot Springs with mineral water pools, whirlpools, a nude cedar sauna and day-pass access.

Scottsdale, Arizona

Adults-only hotel spa at W Scottsdale with thermal circuits, sauna, steam, cold plunge and a robotic Aescape massage option.

Philadelphia, Pennsylvania

Korean-style bathhouse in Cheltenham, just outside Philadelphia, with themed heat rooms, scrub and massage services, and a fitness center.

Calistoga, California

A 1952 Calistoga hot springs resort with three mineral pools at 85, 95 and 104°F, mud baths, overnight rooms and a day-pass option.

Bad Gastein, Salzburg

Open-air thermal baths in Bad Gastein using the town's mineral-rich Gesundwasser, with pools, saunas and a fitness center at 1,100 meters in the Hohe Tauern.

Húsavík, Northeastern Region

Geothermal seawater baths built into the cliffs above Skjálfandi bay in Húsavík, with walk-in day passes and views toward the Arctic horizon.

Thatcher, Idaho

A riverside hot springs in Thatcher, Idaho, with outdoor thermal pools, day passes, and overnight stays in yurts, cabins, or tents.

Olmué, Valparaíso

A boutique lodge and spa in the Olmué valley, about 80 minutes from Santiago, with a thermal pool, outdoor baths and day passes for non-guests.

Mornington Peninsula, Victoria

Adults-only bathhouse in Mornington with magnesium baths, ice plunge, sauna and steam rooms; walk-ins welcome.

Austin, Texas

Day spa in Steiner Ranch, Austin, offering sauna, steam room, thermal pools, cold plunge and a signature scalp treatment for adults, open Monday through

Centreville, Virginia

A Korean jjimjilbang in Centreville, Virginia, with multiple saunas, a bade pool, steam rooms and a restaurant, open daily 8am–10pm with walk-in access.

Budapest

A large thermal bath complex in Budapest's City Park with indoor and outdoor pools, saunas, and day passes for walk-in visitors.

Brežice, Posavje

A large thermal water park in Brežice, Slovenia, with a year-round indoor pool riviera, an adults-only sauna zone, and seasonal outdoor slides.

Palm Springs, California

Downtown Palm Springs day spa built around a natural hot mineral spring, with private mineral baths, sauna, steam room and massage.