Spas with overnight stay

Aix-les-Bains, Auvergne-Rhône-Alpes

Medical thermal baths in Aix-les-Bains treating respiratory and oral mucosal conditions with sulfur-rich water, mostly through prescribed multi-day cures.

Dax, Nouvelle-Aquitaine

Family-run thermal hotel in Dax with a supervised pool, sauna, hammam and a 20-treatment mini-cure over five days, plus day-pass access to the spa.

San Pedro de Atacama, Antofagasta

A hotel spa inside the luxury Tierra Atacama lodge near San Pedro de Atacama, with indoor and infinity pools, sauna, steam room and treatment rooms, open only

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.

Rotorua, Bay of Plenty

A lakefront resort spa in Holdens Bay, Rotorua, with day passes, jacuzzis, sauna and an onsite restaurant, open daily 8am-9pm.

Auckland

A family-run rainforest resort in the Waitakere Ranges near Auckland offering a day spa, private yoga and free hiking and biking trails.

Yalova

Historic Ottoman-era thermal baths in Yalova's Termal district, with day-pass access to pools and private bath cabins.

Luhačovice, Zlín Region

A destination spa in Luhačovice built around mineral springs, offering medical cures, sauna world, outdoor whirlpools and fitness, open daily 7am–8pm.

Wulai, New Taipei

A hilltop Wulai B&B with sodium bicarbonate hot-spring baths in every room and an outdoor infinity pool, geared toward couples.

Carefree, Arizona

A 20-plus-acre desert wellness resort in Carefree, Arizona, with a full spa, pools, and 100-plus weekly fitness and mindfulness classes open to day visitors by

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.

Ginzan Onsen, Yamagata

A riverside hotel spa in Ginzan Onsen with a thermal bathing pool, overnight stay and day-pass access for non-guests.

Koh Samui, Surat Thani

Kamalaya Koh Samui is an adults-only destination spa and wellness retreat on Laem-Set Rd with over 100 treatments, thermal circuits and multi-day health

Thatcher, Idaho

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

Sun Valley, Idaho

A medical spa and wellness retreat in Ketchum offering multi-day longevity programs, practitioner-led recovery and aesthetics, by reservation only.

Oaxaca

A traditional four-door temazcal steam ceremony about 15-20 minutes outside Oaxaca city, paired with an ice-water plunge and overnight rooms.

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

Boutique hotel spa in Desert Hot Springs with two natural mineral hot spring pools, day passes, and overnight rooms that include breakfast.

Hévíz, Zala

A natural thermal lake and medical spa in Hévíz, Hungary, offering mud and weight baths, massage and physiotherapy, open daily 9:00–18:30.

Bagno Vignoni, Tuscany

A 5-star hotel spa resort in Bagno Vignoni with thermal pools, open only to overnight guests staying in the Val d'Orcia countryside.

Rishikesh, Uttarakhand

An upscale riverside resort 18 km outside Rishikesh with an in-house spa, yoga studio and restaurant, open only to overnight guests by reservation.

Phoenix, Arizona

An all-suite Phoenix resort where the spa menu comes bundled with a 7-acre water park, but access is limited to hotel guests.

Holmes Beach, Florida

A beachfront resort on Anna Maria Island with a spa, sauna, steam room and pool, open to hotel guests, mainly geared toward couples.