Spas with hotel guests only

Ein Bokek, Southern District

Hotel spa on the Dead Sea shore in Ein Bokek with a heated mineral-water pool, sulphur pools, hammam and sauna; day passes open to adults 16 and up.

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.

San Juan

Adults-only boutique hotel in San Juan's Santurce/Condado area with a rooftop indoor plunge pool, private suites and a signature couple's massage, priced at

Byron Bay, New South Wales

A moderate-priced day spa at the Elements of Byron resort, open to walk-ins and hotel guests for massages, facials and body rituals.

Palm Springs, California

Adults-only hotel spa at the Parker Palm Springs with 15 private treatment rooms, couples suites and a $300 signature aloe treatment.

Scottsdale, Arizona

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

Boston, Massachusetts

Hotel spa inside Raffles Boston pairing Guerlain facials and massages with a 65-foot lap pool, hot tub, sauna, steam room and three private treatment suites.

Orlando, Florida

Adults-only luxury hotel spa at The Ritz-Carlton Orlando, Grande Lakes, with 40 treatment rooms, couples suites and a lap pool.

Vail, Colorado

Hotel spa at The Arrabelle in Lionshead Village, Vail, with 11 treatment rooms, a fitness center and locker-room steam rooms, open to hotel guests.

Jackson Hole, Wyoming

A hotel spa at Rustic Inn Creekside Resort in Jackson Hole with dry sauna, eucalyptus steam room, outdoor pool and hot tub, open to overnight guests only.

Scuol, Grisons

Hotel spa at the 4-star Belvedere in Scuol with indoor/outdoor pools, mineral and thermal water, sauna, steam bath and a day pass option.

Palm Springs, California

Sante Spa is the adults-only resort spa at the Riviera Palm Springs, with 18 treatment rooms, a Watsu pool, steam room and validated valet parking.

Belize

A beachfront resort on Ambergris Caye, Belize, with three pools, a pool bar and day-pass access to its pool and ocean-view grounds.

Palm Beach, Florida

A hotel spa at the Palm Beach Marriott Singer Island resort offering massages, facials and body treatments, open daily 9am–6pm, guests 16+ only.

Biarritz, Nouvelle-Aquitaine

A 2,500 m² ocean-facing spa inside Biarritz's historic Hôtel du Palais, with a counter-current freshwater pool, sauna, hammam and Guerlain treatments, open to

Park City, Utah

A 27-room resort spa at Montage Deer Valley in Park City, open to hotel guests with a pool, steam room, sauna and cold plunge.

Naples, Florida

A 4,500-square-foot beachfront spa at LaPlaya Resort in North Naples offering massages, facials and nail services, open daily 9am-5pm.

Sapporo, Hokkaido

Natural hot spring inside Sapporo's Jasmac Plaza Hotel in Susukino, open to day visitors and hotel guests alike, with sauna and a rest lounge.

Dubai

A hotel spa inside Jumeirah Zabeel Saray on Palm Jumeirah built around a Turkish-style hammam, thalassotherapy pool and couples treatments.

Tuscany

A five-star resort in the Tuscan countryside built around a natural thermal spring, with day passes from €39 for outdoor thermal pools, hydromassage circuits

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

Santa Fe, New Mexico

A hotel spa inside a historic adobe inn in downtown Santa Fe, with private treatment suites reserved for overnight guests only.

Santa Barbara, California

A 42,000-square-foot hotel spa in Santa Barbara with an adults-only pool, redwood sauna, eucalyptus steam room, cold plunge and rooftop terrace.

Los Angeles, California

Downtown LA hotel spa at the Ritz-Carlton with massages, facials, a couples suite, rooftop pool and gym; outside guests need to book a treatment to enter.