Spas with family friendly

Baden-Baden, Baden-Württemberg

Modern thermal baths in Baden-Baden with indoor-outdoor pools and a Roman-style sauna garden, open daily 8am–10pm, day pass €40.

San Miguel de Allende, Guanajuato

Family-friendly hot springs park near San Miguel de Allende with indoor and outdoor thermal pools, a kids' splash area, and day passes for walk-ins.

Atlanta, Georgia

Korean day spa in Norcross near Atlanta with hot and cold baths, sauna rooms, salt room and a restaurant; day pass runs $30.

Vail, Colorado

Hotel spa and recovery club in Vail Village with hot tubs, cold plunge, sauna, salt room and a gym, open to day-pass visitors.

Reykjavik, Capital Region

Eight oceanfront geothermal pools in Hvalfjörður, 45 minutes from Reykjavík, plus steam baths, a bistro and guest houses for rent.

Ischia, Campania

Family-run thermal pool park on Ischia's Maronti beach, open since 1973, with three sulfur-water pools, a sauna and direct beach access.

Byron Bay, New South Wales

A moderate-priced day spa at the Elements of Byron resort, open to walk-ins and hotel guests for massages, facials and body rituals.

St. Moritz, Grisons

An indoor-outdoor pool and spa complex in St. Moritz-Bad with four pools, three slides, a sauna zone, fitness center and bike/Nordic hub under one roof.

Shibu Onsen, Nagano

Reservation-only private hot spring and sauna suites at a Nagano brewery complex, built around a craft beer bathing plan for two to four guests.

Dallas, Texas

Korean-style day spa in Carrollton with hydrotherapy pools, saunas and relaxation lounges, open daily 9am–9:30pm with walk-in day passes.

Austin, Texas

Hotel spa at Hotel Viata in West Lake Hills with treatment rooms, a couples suite, pool, sauna, steam room and a day-pass option for amenity access.

Sárvár, Vas

A large thermal and wellness complex in Sárvár with indoor and outdoor medicinal pools, slides, a sauna world, fitness center and massage treatments.

Merano, Trentino-South Tyrol

Central thermal bath complex in Merano with 25 pools, a sauna world, thermal park and medical spa area, open daily year-round with walk-in day passes.

Philadelphia, Pennsylvania

Hotel spa in Center City Philadelphia with a heated indoor saltwater pool, fitness center and day-pass access for non-guests.

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.

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.

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.

Asheville, North Carolina

Resort spa on an 85-acre Hendersonville farm near Asheville, with massage treatments in a converted horse barn, day passes, and a pool with sauna, steam and

Catskills, New York

A resort spa in Mt Tremper, Catskills, offering treatments, a relaxation lounge and dining, open to both day-pass visitors and hotel guests.

Karjalohja, Uusimaa

Lakeside resort spa on Lohjanjärvi in Karjalohja, about an hour from Helsinki, with a day pass, thermal pool, salt room and restaurant.