Spas with upscale

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.

Tenerife, Canary Islands

A hotel spa at Bahía del Duque in Costa Adeje with an outdoor seawater thalassotherapy circuit, hammam, saunas and a cold plunge, open to day visitors.

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.

San Francisco, California

A hotel spa at Fort Baker near Sausalito for Cavallo Point guests, with a meditation pool, Zen garden, infrared sauna and outdoor Jacuzzis.

Chicago, Illinois

Adults-only hotel spa in River North with a 67-foot pool, multiple sauna and steam rooms, and day passes for non-guests.

Miami, Florida

Hotel spa inside Dua Miami, Autograph Collection in Brickell, open daily 9am-6pm, with sauna, steam room, cold plunge and couples massage rooms.

Doha

Hotel spa at The Westin Doha with some of the city's largest wet facilities, accessible to hotel guests and members only, no day passes sold.

Scottsdale, Arizona

Adults-only hotel spa at The Scott in Scottsdale with six treatment rooms, sauna, steam and pools, plus day passes for non-guests.

Tucson, Arizona

Hotel spa at Loews Ventana Canyon Resort, Tucson, with eight treatment rooms, an adults-only pool, and a 24-hour fitness center; open daily 9am–6pm.

Chicago, Illinois

Hotel spa on the lower level of the Fairmont Chicago, open to guests for massages, facials and a couples suite with an infinity-edge soaking tub.

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.

Miami, Florida

Adults-only spa and pool complex inside Loews Miami Beach Hotel, open to hotel guests only, with sauna, steam, cold plunge and thermal circuits.

Scottsdale, Arizona

Adults-only resort spa at the Andaz Scottsdale with treatment suites, a private pool, fitness center and cabana bookings, day pass available.

Punta Cana, La Altagracia

Punta Cana Princess is an adults-only, all-inclusive resort spa in Bávaro, open to hotel guests only with free on-site parking.

Lombok, West Nusa Tenggara

A hotel-guest-only wellness room at Rascals in Kuta, Lombok, with a traditional sauna, dual ice baths and a magnesium pool, open daily 8am–9:30pm.

Las Vegas, Nevada

Adults-only hotel spa inside Westgate Las Vegas offering massages, facials, salon services, sauna, steam room and a thermal pool, open daily 9am-6pm.

Lake Tahoe, California

Adults-only hotel spa at Edgewood Tahoe with gemstone massage rituals, an oxygen bar, and treatment-only access to the facility.

Miami, Florida

A 12,000-square-foot hotel spa at Coral Gables' Biltmore, with eucalyptus steam rooms, Himalayan salt saunas and a couples suite; adults-only, reservation

Orlando, Florida

Adults-only hotel spa at Disney's Grand Floridian Resort with massage, salon services and a fitness center, open to walk-ins daily 9am-6pm.

Calistoga, California

Hotel spa in downtown Healdsburg with a garden patio, jacuzzi and pool access, open daily 9am-5pm for guests and day visitors.

Chicago, Illinois

A hotel spa on Trump Chicago's mezzanine level offering day passes, 22 treatments, a heated pool, steam room, sauna and fitness club; minimum age 16.

Las Vegas, Nevada

A two-floor hotel spa inside Vdara with steam room, sauna, whirlpool and lounge, open only to Vdara and ARIA guests 18 and older, closed Tuesdays.

Brussels

Hotel spa on the 25th floor of The Hotel Brussels, with city views, sauna, steam room, salt sauna and a Technogym fitness floor.

Scottsdale, Arizona

Hotel spa inside Hotel Solaya in South Scottsdale built around Tod Miller's proprietary BodyWalking compression technique, with four treatments and a $335