Spas with moderate

Philadelphia, Pennsylvania

A Russian-Turkish bathhouse in Southampton, outside Philadelphia, with platza massage, a pool and multiple heat rooms, open to walk-ins with day passes.

San Diego, California

Adults-only day spa at Mission Bay Resort with massage, facials, Himalayan salt treatments and couples suites; walk-ins and day passes welcome.

Washington, D.C., District of Columbia

Downtown K Street day spa in DC offering massage, facials, infrared sauna and a salt therapy lounge, open daily 10am-8pm with day passes available.

Nashville, Tennessee

A Berry Hill day spa in Nashville offering massage, facials, body treatments and a sauna pod/salt room, open Tuesday through Saturday.

Los Angeles, California

A Westlake day spa built around themed sauna rooms—salt, gold, Loess soil, Elvan stone, forest and ice—plus a waterfall feature and garden.

Tucson, Arizona

Adults-only hotel spa at El Conquistador Tucson with a salt therapy lounge, heated outdoor pool and mountain views, day passes available to hotel guests.

Asheville, North Carolina

A trauma-informed day spa in Asheville's Haw Creek neighborhood with saltwater floatation tanks, massage, infrared sauna and facials; walk-ins welcome.

Sapporo, Hokkaido

Natural hot spring inside Sapporo's Jasmac Plaza Hotel in Susukino, open to day visitors and hotel guests alike, with sauna and a rest lounge.

Arima Onsen, Hyogo

A moderately priced onsen bathhouse in Arima Onsen, Kobe, with a forest sauna, a large outdoor bath, yoga and an award-recognized restaurant.

Sárvár, Vas

Large thermal bath complex in Sárvár with indoor and outdoor pools, a sauna world, slides for kids, and medical spa treatments.

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.

Bad Wörishofen, Bavaria

Adults-only thermal baths in Bad Wörishofen with palm-house pools, mineral pools and saunas; day passes available, minimum age 16.

Tbilisi

A medical spa in Old Tbilisi built around natural sulfur-mineral water and volcanic mud, operating since 1938, open daily 10am–9pm.

Puyehue, Los Lagos

A hot-springs resort inside Puyehue National Park with two mineral pools, cabins, river-side domes, camping, and day passes for non-guests.

Chaves, Norte

Thermal baths complex in Chaves, Portugal, built around natural hot springs, with hydrotherapy, sauna, steam room and massage on a day-pass basis.

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.

Portorož, Coastal-Karst

Thermal baths and seawater pools in Portorož, open daily 7am–9pm with walk-in day passes and a large sauna park.

Chianciano Terme, Tuscany

Thermal day spa in Chianciano Terme offering day passes, couples massages and a wellness-food menu, closed Thursdays and Wednesdays.

Boston, Massachusetts

A Norwood, Massachusetts day spa built around a hot-cold hydrotherapy circuit of mineral baths, saunas, steam and cold plunges, open daily with a day pass.

Portland, Oregon

An 18-and-up, clothing-optional spa in Portland's Kerns neighborhood with a salt hot tub, sauna, steam room and cold plunge, reservation required.

Taos, New Mexico

Hotel day spa at El Monte Sagrado in Taos with a hydrotherapy circuit, saltwater pool and treatment rooms, open daily, day passes available.

Los Angeles, California

A Silver Lake day spa with 20 treatments, Thai massage, acupuncture and a salt-infused infrared sauna, open daily 10am-9pm.

New York City, New York

Korean jjimjilbang-style spa in Manhattan with saunas, steam room, soaking tub and body scrubs, open daily 8am-11:30pm on a day-pass basis.

Las Vegas, Nevada

A Summerlin day spa centered on Himalayan salt rooms, plus massage, facials and Reiki, open daily 10am-7pm.