Spas with hotel guests only

Las Vegas, Nevada

Adults-only hotel spa inside ARIA Resort & Casino in Las Vegas, with sauna, steam room, thermal pools and cold plunge, open to hotel guests 18 and up.

Buenos Aires

A hotel spa inside the Palacio Duhau-Park Hyatt in Barrio Norte, open only to hotel guests, with Mapuche-inspired treatments and a semi-olympic pool.

Ainsworth, British Columbia

A lakeside hot springs resort in British Columbia's Kootenays with public thermal pools, a spa, restaurant and overnight rooms, closed Tuesdays.

Bagno Vignoni, Tuscany

Hotel spa in a 15th-century Bagno Vignoni palazzo with a thermal pool fed by the village's natural hot springs, open to day visitors.

Santiago, Santiago Metropolitan

A hotel spa in Macul, Santiago, with thermal pools, sauna, steam room and cold plunge, open to hotel guests only, no day passes offered.

Längenfeld, Tyrol

A large thermal bath and 4-star hotel spa in the Ötztal valley near Längenfeld, with indoor-outdoor pools, a sauna garden and a dedicated kids' water world.

Sacred Valley, Cusco

A 115-room hotel built into a 17th-century colonial hacienda in Peru's Sacred Valley, with an on-site spa open only to overnight guests.

Daylesford, Victoria

A rammed-earth house on 80 hectares near Daylesford, rented whole for up to 10 adults, with in-room massage and a two-night minimum 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.

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.

O Grove, Galicia

A thermal spa on Isla de la Toja combining a seawater hydrotherapy circuit with a mineral-medicinal water balneario, open daily with a day pass option.

Doha

Hotel spa inside Banyan Tree Doha with separate men's and women's hydrothermal suites, open daily 10am-11pm to hotel guests only.

Calistoga, California

A moderate-priced resort spa in Calistoga with geothermal mineral pools, open daily 9am-5pm and offering day passes to the public.

Miami, Florida

A luxury day-pass wellness circuit inside Carillon Miami Wellness Resort, with sauna, steam, cold plunge and thermal pools in North Beach.

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.

Las Vegas, Nevada

A 134,000-square-foot spa and fitness center inside The Venetian Resort, with over 100 treatments, thermal experiences and day passes for non-guests.

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.

Karlovy Vary, Karlovy Vary Region

A 5-star medical spa and wellness hotel beside Karlovy Vary's colonnades, with seven saunas, five pools and a day pass for non-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.

Riviera Maya, Quintana Roo

Adults-only hotel spa at Devossion by Live Aqua in Playa del Carmen, open daily 8am-8pm, with sauna, steam room and pools for resort guests.

Marrakech, Marrakesh-Safi

A 1,200-square-metre hotel spa at Selman Marrakech built around the Chenot method, with hammams, pools and multi-day wellness programmes.

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.

Stockholm, Stockholm County

A hotel spa on Södermalm with indoor and outdoor pools, a dry sauna and a steam room, open to day-pass visitors aged 16 and up.

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.