Spas with thermal pool

Nashville, Tennessee

A hotel wellness area at Sheraton Music City near Nashville airport, open to guests 21 and up, with sauna, steam room, pools and a whirlpool.

The Hamptons, New York

Adults-only destination spa and 12-room retreat in Water Mill, offering hydrotherapy, yoga, spa treatments and overnight stays by reservation.

Tyrol, Bavaria

Hotel spa in Kreuth-Reitrain near Tegernsee with a 3,000 sqm onsen-style bathing area, hot and cold pools, saltwater pools and sauna, open on a day-pass basis.

Jerusalem, Jerusalem District

A hotel spa in Jerusalem with sauna, hot tub and thermal pool, open to walk-ins and day-pass guests most days of the week.

Wanaka, Otago

Adults-only hot springs with thermal pool and sauna in Wānaka, open for day passes most evenings and Saturday afternoons, closed Sundays.

Miami, Florida

A large hotel wellness resort on North Beach with a European-style hydrotherapy circuit, cryotherapy, acupuncture and an oceanfront fitness center.

Napa Valley, California

Adults-only resort spa in Napa Valley with pools, sauna, steam and a fitness center, open to hotel guests and club members via day pass.

Edinburgh, Scotland

Hotel spa inside The Caledonian on Princes Street with a thermal pool, sauna, steam room and relaxation lounge, open daily 6am to 9pm.

Phoenix, Arizona

Adults-only hotel wellness setup in downtown Phoenix with a heated pool, sauna and steam room, day passes available for $50.

Bad Ragaz, St. Gallen

A resort thermal spa in Bad Ragaz with indoor and outdoor thermal pools and sauna, open daily 7:30am–8pm, reservation required for day passes.

Tucson, Arizona

A hotel spa at an 80-acre Sonoran Desert resort in Tucson, open to overnight guests, with three pools, hot tubs, sauna and yoga classes.

Sedona, Arizona

Hotel spa at Hilton Sedona Resort at Bell Rock offering day passes with a relaxation lounge, steam room, sauna and thermal pool, open daily 6am-8pm.

Buxton, England

A hotel spa built into Buxton's historic Crescent, centred on a thermal pool, hydrotherapy circuit and salt room, open to hotel guests only.

Ubud, Bali

A 22-acre riverine-forest wellness retreat outside Ubud built around a sacred spring, accessible only to guests staying at the estate.

Sedona, Arizona

Hotel spa near Bell Rock in Sedona with sauna, steam room, cold plunge and pools, open to resort guests only.

Boston, Massachusetts

A hotel spa inside Mandarin Oriental, Boston's Back Bay property, open to hotel guests only, with sauna, steam room, pools and a cold plunge.

Ramona, California

A vacation-rental resort in Ramona whose day-spa access, sauna, steam room and heated pool are reserved for guests staying on the property.

Los Angeles, California

A hotel spa at Shade Hotel Redondo Beach with sauna, steam, pools, cold plunge and thermal circuits, open to hotel guests overlooking the marina.

Arima Onsen, Hyogo

Hotel spa in Arima Onsen with Arima's rare iron-rich "ginsen" waters, outdoor baths, sauna and jacuzzi, run as an all-inclusive overnight stay.

San Diego, California

Hotel spa at Carté Hotel San Diego Downtown with a heated saltwater pool, whirlpool, 28,000 sq ft fitness club with sauna and steam room, open to guests only.

Oaxaca

An all-inclusive beachfront resort spa in Huatulco with a sauna, steam room and thermal pools, open only to hotel guests.

Miami, Florida

A hotel spa at Eden Roc Miami Beach in Mid-Beach with sauna, steam room, cold plunge and thermal circuits, open to resort guests only.

Calistoga, California

A 25-room Sonoma hotel in Forestville with a spa barn offering sauna, steam and pools, mainly for overnight guests.

Catskills, New York

A Catskills retreat center with a Tibetan-style spa offering sauna, steam, pools and cold plunge, built around overnight stays and group programs.