Spas with hotel guests only

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.

Philadelphia, Pennsylvania

Hotel spa in Center City Philadelphia with a heated indoor saltwater pool, fitness center and day-pass access for non-guests.

Brussels

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

Boston, Massachusetts

Hotel spa inside the Four Seasons One Dalton in Back Bay, with six treatments, a couples' suite and a 64-foot lap pool, open to hotel guests.

Jackson Hole, Wyoming

A small, guests-only spa tucked inside the White Buffalo Club, a luxury boutique hotel three blocks from Jackson's Town Square.

Atlanta, Georgia

Hotel spa in Buckhead with 13 treatments, a heated lap pool, steam room and day passes for non-guests, set inside The Whitley.

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

Merano, Trentino-South Tyrol

An adults-only, guests-only longevity retreat and hotel spa in Merano with a medical-led wellness institute and private suite treatments.

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.

Orlando, Florida

A hotel spa at Waldorf Astoria Orlando offering massages, facials and a Himalayan salt room, open daily 9am-5pm with day passes available.

Bled, Upper Carniola

Hotel spa at Bled's Rikli Balance Hotel with six pools, six saunas and lake views, open to hotel guests only.

Yalova

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

Houston, Texas

Hotel spa at Hotel ZaZa in Houston's Museum District, with massages, body treatments, infrared saunas and day-pass access to the pool lounge.

Orlando, Florida

Adults-only hotel spa at the Hilton Orlando with a sauna, steam room, cold plunge and thermal pools, plus couples treatments and HydraFacials.

Miami, Florida

A 20th-floor hotel spa in Downtown Miami's JW Marriott Marquis offering massages, facials, body treatments and separate men's and women's lounges.

Miami, Florida

Hotel spa inside the InterContinental Miami, open daily with a day pass option, 11 treatments and a signature Raindrop Massage.

New Delhi, Delhi

neoVeda Spa is the in-house spa at The Metropolitan Hotel in Connaught Place, offering Ayurvedic treatments, shirodhara and massage to hotel guests.

Tel Aviv, Tel Aviv District

Hotel spa inside Hotel Drisco Tel Aviv on Ben Yehuda Street, with rooftop baths, a Jacuzzi and couples' treatment rooms.

Vals, Grisons

Peter Zumthor's quartzite thermal baths in Vals, built into the mountain, open to day visitors as well as hotel guests.

Bridgetown, Christ Church

Hotel spa at Accra Beach Hotel in Christ Church, Barbados, with six treatment rooms, a sauna and steam room, open daily 8am-7pm for hotel guests.