Spas with thermal pool

Guanacaste, Río Negro

Riverside volcanic hot springs with ten thermal pools and mud baths near Rincón de la Vieja volcano in Guanacaste, Costa Rica.

Phoenix, Arizona

An all-suite Phoenix resort where the spa menu comes bundled with a 7-acre water park, but access is limited to hotel guests.

Geneva

Public lakefront baths in Geneva offering an outdoor pool, swimming access to the lake, and saunas, with affordable walk-in entry daily.

Băile Herculane, Caraș-Severin

Hotel-based thermal spa in Băile Herculane with sulfur mineral baths, indoor and outdoor pools, jacuzzi and sauna, open to hotel guests.

Băile Herculane, Caraș-Severin

A 4-star hotel in central Băile Herculane with thermal pools, saunas, balneo and physiotherapy treatments, open to overnight guests.

Puyehue, Los Lagos

A forest resort spa in Puyehue, Chile, with volcanic thermal pools and outdoor baths, open only to hotel guests.

Jiaoxi, Yilan

A walk-in fish-spa pool in Jiaoxi's Tangweigou hot spring strip, offering affordable thermal soaking with doctor fish for families.

Tucson, Arizona

Lakeside Spa at this 398-room desert resort in Tucson is open to hotel guests only, with two heated pools, a Jacuzzi and mountain views of Catalina range.

Hot Springs, Arkansas

A café and lounge inside Thai-Me Spa in downtown Hot Springs, with outdoor mineral soaking spas, cold plunge and sauna access nearby.

Bad Ischl, Upper Austria

A salt-and-brine thermal bath complex in Bad Ischl with indoor/outdoor pools, a sauna world, and a rooftop wellness deck at the attached hotel.

Fort Lauderdale, Florida

Hotel spa at The Atlantic Resort on Fort Lauderdale Beach with sauna, steam room, cold plunge and thermal pool, for overnight guests only.

Charlotte, North Carolina

A moderate-priced day spa in Charlotte's SouthPark area with a sauna, steam room and thermal pool alongside massage, facial and body-treatment menus.

Băile Felix, Bihor

Strand Apollo-Felix is a year-round thermal pool complex in Băile Felix, Romania, with indoor and outdoor pools open daily from 8am to 8pm.

Tekapo, Canterbury

Outdoor hot pools, a cooler soak and a kids' aqua play area beside Lake Tekapo, with walk-in day passes and an on-site café.

Hot Springs, Arkansas

A day spa on Central Avenue in Hot Springs with outdoor mineral soaking tubs, cold plunge, infrared sauna, massage and an on-site café.

Baden bei Wien, Lower Austria

A thermal bath in Bad Vöslau with four mineral-water pools fed by the original Vöslauer spring, plus sauna and steam room.

Guanziling, Tainan

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

Asan, South Chungcheong

Hot springs resort spa in Asan with thermal pools, sauna and a relaxation lounge, open daily on a walk-in day-pass basis.

Beitou, Taipei

Hotel spa in Beitou with a thermal pool, open to day-pass visitors as well as hotel guests.

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.

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.

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.

Termas de Río Hondo, Santiago del Estero

An all-inclusive family resort in Termas de Río Hondo with thermal pools, a spa and buffet dining, open to hotel guests only.

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.