Spas with thermal pool

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.

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.

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.

Carson, Washington

A clothing-optional, adults-only mineral hot springs bathhouse in Carson, Washington, with a $12 day pass and a $30 bath-and-wrap treatment.

Manuel Antonio, Puntarenas

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

Thermopolis, Wyoming

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

Jemez Springs, New Mexico

Walk-in outdoor mineral hot springs in Jemez Springs, NM, with four pools kept between 98 and 105°F and a $25 one-hour day pass.

San Miguel de Allende, Guanajuato

A Saturday-only hot springs day spa near San Miguel de Allende with outdoor thermal pools and walk-in access.

Dead Sea, Balqa

Resort spa on the Dead Sea shore with 40 treatments, thermal pools, sauna and steam, open to day guests aged 16 and up.

Asan, South Chungcheong

A hot springs facility in Asan with thermal pools, hot tubs and saunas, open to walk-ins and suited to families.

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.

Reykjavik, Capital Region

An oceanfront thermal bath in Kópavogur near Reykjavik, open daily with outdoor pools facing the sea and walk-in day passes.

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.

Hot Springs, Arkansas

An 1889 bed-and-breakfast across from Hot Springs National Park, with in-room whirlpool tubs for two rather than a communal bathhouse.

Sáchica, Boyacá

Natural thermal pools and a relaxation lounge at the edge of Villa de Leyva, open daily except Wednesday with day passes for families and couples.

Ourense, Galicia

An outdoor hot-springs spa in Ourense with thermal pools, walk-in day passes, and hours that run late on weekends.

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.

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.

Chianciano Terme, Tuscany

Hotel spa in Chianciano Terme open to non-guests, built around a 450 sqm holistic water, color and massage circuit.