Spas with thermal pool

Philadelphia, Pennsylvania

Korean-style bathhouse in Cheltenham, just outside Philadelphia, with themed heat rooms, scrub and massage services, and a fitness center.

Calistoga, California

A 1952 Calistoga hot springs resort with three mineral pools at 85, 95 and 104°F, mud baths, overnight rooms and a day-pass option.

Banff, Alberta

Luxury hotel spa inside Fairmont Banff Springs offering thermal pools, steam rooms and treatments, open daily with day passes for non-guests.

Bad Gastein, Salzburg

Open-air thermal baths in Bad Gastein using the town's mineral-rich Gesundwasser, with pools, saunas and a fitness center at 1,100 meters in the Hohe Tauern.

Húsavík, Northeastern Region

Geothermal seawater baths built into the cliffs above Skjálfandi bay in Húsavík, with walk-in day passes and views toward the Arctic horizon.

Granada, Andalusia

A traditional-style hammam in central Granada with a heated thermal pool and relaxation lounge, open daily from 9am to midnight.

Koh Samui, Surat Thani

Kamalaya Koh Samui is an adults-only destination spa and wellness retreat on Laem-Set Rd with over 100 treatments, thermal circuits and multi-day health

Chicago, Illinois

Upscale day spa in Lincoln Park, Chicago, where booking any treatment unlocks all-day access to a hydrotherapy circuit, thermal suite and outdoor terrace.

Thatcher, Idaho

A riverside hot springs in Thatcher, Idaho, with outdoor thermal pools, day passes, and overnight stays in yurts, cabins, or tents.

Olmué, Valparaíso

A boutique lodge and spa in the Olmué valley, about 80 minutes from Santiago, with a thermal pool, outdoor baths and day passes for non-guests.

Amalfi Coast, Campania

An adults-only day spa in Minori on the Amalfi Coast built around a thermal pool, open daily 11am to 8pm by reservation.

Chicago, Illinois

A West Town day spa built around a beer soak, with sauna, steam room, salt room and thermal pool for couples or solo visits.

Mornington Peninsula, Victoria

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

New York City, New York

A five-treatment-room hotel spa inside The Greenwich Hotel in Tribeca, built around a heated pool and Japanese-influenced design.

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

Centreville, Virginia

A Korean jjimjilbang in Centreville, Virginia, with multiple saunas, a bade pool, steam rooms and a restaurant, open daily 8am–10pm with walk-in access.

Budapest

A large thermal bath complex in Budapest's City Park with indoor and outdoor pools, saunas, and day passes for walk-in visitors.

Brežice, Posavje

A large thermal water park in Brežice, Slovenia, with a year-round indoor pool riviera, an adults-only sauna zone, and seasonal outdoor slides.

Palm Springs, California

Boutique hotel spa in Desert Hot Springs with two natural mineral hot spring pools, day passes, and overnight rooms that include breakfast.

Palm Springs, California

Downtown Palm Springs day spa built around a natural hot mineral spring, with private mineral baths, sauna, steam room and massage.

Berlin

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

Ibiza, Balearic Islands

A budget-friendly day spa in Eivissa with heated indoor pools, a hammam, sauna and ice fountain, open to walk-ins for €20.

Tulum, Quintana Roo

Members-only contrast-therapy spa in La Veleta, Tulum, with a dry sauna, cold plunge, hot tub and a quiet pool for adults only.

Ojo Caliente, New Mexico

Historic New Mexico hot springs resort with communal mineral pools, private tubs, and day-pass soaking near Taos.