Spas with overnight stay

Palm Springs, California

Adults-only hot springs resort on Miracle Hill in Desert Hot Springs with private mineral tubs, a Finnish sauna, salt room and 35 spa treatments.

Sonoma, California

A small hotel spa inside Cottage Inn and Spa in downtown Sonoma, offering seven massage and body treatments with a relaxation lounge and couples option.

Miami, Florida

A beachfront resort spa in North Beach, Miami with cryotherapy, a floating salt bath, sauna, steam and a cold plunge, open to walk-ins and day-pass guests.

Florence, Tuscany

A 650-square-meter spa inside a 14th-century Florence monastery, with thermal pool, guesthouse rooms, bistro and day-pass access.

Krynica-Zdrój, Lesser Poland

Mountain resort spa in Krynica-Zdrój with indoor and outdoor pools, a sauna complex, and a clothing-optional 18+ zone; day passes available.

Bursa

A historic thermal bathhouse and small hotel in Bursa's Kükürtlü district, with separate men's and women's hamams, day passes, and overnight stays.

Saint-Malo, Brittany

A seafront thalassotherapy center in Saint-Malo with an Aquatonic seawater pool circuit, day passes, and multi-day cure packages in a Belle-Époque building.

Pärnu, Pärnu County

A 193-room medical spa hotel in Pärnu with a pool and sauna complex, salt therapy, physiotherapy and water aerobics, open to day visitors.

Sierraville, California

A non-profit hot springs retreat near Lake Tahoe with natural spring pools, reservation-only day and evening soaks, camping and rooms, closed Mondays and

Miami, Florida

Adults-only hotel spa on Belle Isle near South Beach with a hammam, sauna, ice room, infinity pool and a day pass option for non-guests.

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.

Auckland

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

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

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.

Leukerbad, Valais

Thermal baths inside a 19th-century hotel in Leukerbad, Valais, with mineral-rich pools open daily from 9am to 8pm.

Vals, Grisons

Peter Zumthor's quartzite thermal baths in Vals, fed by a 30°C mineral spring, open to day visitors as well as hotel guests.

Scottsdale, Arizona

Adults-only resort spa in Fountain Hills with sauna, steam room and outdoor pools, offering day passes and an amethyst facial as its signature treatment.

Portland, Oregon

Adults-only hotel and thermal springs on NE Alberta St in Portland, with vitality pools, a day-pass option, and spa treatments.

Carson, Washington

A clothing-optional, adults-only mineral hot springs bathhouse in Carson, Washington, with a $12 day pass and a $30 bath-and-wrap treatment.

Jerusalem, Jerusalem District

An adults-only resort spa in the Judean Hills outside Jerusalem, with indoor and outdoor pools, a hammam and a day-pass option.

San Juan

Adults-only hotel spa inside La Concha Resort in Condado, San Juan, offering couples massages and a small treatment menu for guests 18 and up.

Austin, Texas

Adults-only resort spa on Lake Austin offering all-inclusive overnight stays and limited day passes to pools, saunas, steam rooms and lake activities.