Spas with thermal pool

Mornington Peninsula, Victoria

Adults-only bathhouse in Mornington with magnesium baths, ice plunge, sauna and steam rooms; walk-ins welcome.

Austin, Texas

Day spa in Steiner Ranch, Austin, offering sauna, steam room, thermal pools, cold plunge and a signature scalp treatment for adults, open Monday through

Berlin

A saltwater thermal pool under a concrete dome near Berlin's Tempelhofer Feld, with sauna, steam room and occasional DJ nights.

Puelo, Los Lagos

Adults-only hot springs in Puelo with ten thermal pools, a sauna, steam room and individual herbal tubs, open daily with walk-in day passes.

Milwaukee, Wisconsin

East Town Spa in Milwaukee's Juneau Town combines a full-service salon and med spa with a thermal circuit of sauna, steam, pools and cold plunge.

Milan, Lombardy

Adults-only day spa in a Liberty-style building near Milan's Parco Sempione, with thermal pools, saunas, steam room and a hydrotherapy circuit.

Minneapolis, Minnesota

A moderate-priced day spa in Minnetonka with a sauna, steam room, thermal pool and cold plunge, set up for couples and adults-only visits.

Portland, Oregon

Adults-only hotel and thermal springs on NE Alberta St in Portland, with vitality pools, a day-pass option, and spa treatments.

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.

Granada, Andalusia

An Arab-style bathhouse in Granada's Centro district with thermal pools and a relaxation lounge, open daily 10am–10:30pm, adults only.

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.

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.

San Francisco, California

An adults-only bathhouse in San Francisco's Tenderloin with a thermal pool and an on-site restaurant, open daily except Tuesdays.

New York City, New York

Adults-only day spa on Governors Island with heated outdoor pools, saunas and an Italian-style café, reachable by ferry from Manhattan.

Wanaka, Otago

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