Spas with thermal pool

Guanziling, Tainan

A grayish mud hot spring in Baihe, Tainan, with outdoor baths and a thermal pool, open daily from 9am to 11:30pm.

Palm Beach, Florida

An oceanfront resort spa in Riviera Beach combining Ayurvedic treatments with a hydrothermal circuit, hammam, salon and private beach access.

Redstone Historic District, Colorado

A ranch property in Colorado's Crystal River Valley with three tiered natural hot springs pools open to day visitors and overnight guests alike.

Bad Reichenhall, Bavaria

Bavarian State Spa authority operating Bad Reichenhall's thermal bath, with a thermal pool, sauna area and separate family pool, open on a day-pass basis.

Băile Felix, Bihor

A thermal baths complex in Băile Felix with outdoor and indoor pools, open daily with walk-in access and no membership required.

Many, Louisiana

Hotel spa at Cypress Bend Resort on Toledo Bend Lake in Many, Louisiana, with a sauna, hot tub, and heated indoor and outdoor pools.

South Haven, Michigan

An adults-only glamping resort and pool club at South Haven Country Club with a day-pass spa area featuring a pool, sauna and relaxation lounge.

Manuel Antonio, Puntarenas

A destination spa with outdoor thermal pools near Manuel Antonio, Costa Rica, open daily with reservations required.

San Diego, California

Adults-only hotel spa in Carmel Valley with sauna, steam, cold plunge and thermal circuits, open to guests of the Fairmont Grand Del Mar.

Vancouver, British Columbia

A hotel spa inside Fairmont Pacific Rim in downtown Vancouver, with sauna, steam, pools, cold plunge and thermal circuits, open to hotel guests only.

Riviera Maya, Quintana Roo

Resort spa at the Fiesta Americana Cozumel with sauna, steam room, cold plunge and couples treatments, open to hotel guests only.

Scottsdale, Arizona

Adults-only resort spa in Scottsdale with sauna, steam, cold plunge and thermal pools, open only to hotel guests.

Riviera Maya, Quintana Roo

Beachfront all-inclusive resort in Playa del Carmen with a hydrothermal circuit spa available to hotel guests for an extra charge.

San Diego, California

A hotel spa at the Handlery Hotel in Mission Valley, San Diego, with sauna, steam room, cold plunge and thermal pools for guests.

Calistoga, California

A clothing-optional hot springs retreat outside Calistoga with eight mineral pools, spa bodywork, and day-pass, camping, and lodging options.

San Diego, California

A 21-and-over hotel spa in San Diego's Gaslamp Quarter with sauna, steam room, cold plunge and thermal pools, open to hotel guests only.

Los Baños, Laguna

A natural spring resort near Mount Makiling in Calauan, Laguna, with outdoor pools, forest trails, and day passes offered every day of the week.

Cancún, Quintana Roo

A boutique hotel near Cancún airport with a small wellness wing — pool, jacuzzi, sauna, steam room and temazcal — open to day-pass visitors.

Thermopolis, Wyoming

Free public bathhouse in Thermopolis, Wyoming, with indoor and outdoor mineral soaking pools held at 104°F, open seven days a week.

San Antonio, Texas

Full-service resort spa at the Hyatt Regency Hill Country in San Antonio, with thermal circuits, cold plunge and day passes open to non-guests.

Riviera Maya, Quintana Roo

A resort spa inside the Iberostar Waves Tucán in Playacar offering sauna, Turkish bath and jet-pool treatments, open to day-pass visitors 16 and up.

Calistoga, California

A historic hot-springs resort in Calistoga with an early-1900s mineral pool, mud baths, and a public restaurant, but spa access is limited to hotel guests.

Miami, Florida

A hotel spa in downtown Miami with a day pass covering sauna, steam, cold plunge and thermal pools, plus 13 treatments on the menu.

San Juan

Adults-only hotel spa inside La Concha Resort in Condado, San Juan, offering couples massages and a small treatment menu for guests 18 and up.