Spas with adults only

Hot Springs, Arkansas

Thermal-water bathhouse on Central Ave in Hot Springs offering soaking pools, private mineral baths and eight spa treatments, minimum age 14.

Denver, Colorado

Bathhouse in Denver's Ballpark District built around contrast therapy: a 40-person cedar sauna, eucalyptus steam room, five cold plunges, and thermal soaking

Seattle, Washington

A clothing-optional outdoor hot pool, sauna and sun deck in Seattle's West Woodland, open to walk-ins for three-hour day visits.

Sonoma, California

A boutique day spa in downtown Sonoma centered on infrared sauna and cold plunge drop-ins, plus massage, red light and PEMF therapy.

Auckland

Hotel day spa at Pullman Auckland CBD with a 25m heated pool, sauna, steam room, jacuzzi and gym plus massage and facial treatments.

Duluth, Georgia

Korean jjimjilbang in Duluth near Atlanta with hot and cold tubs, saunas, and a food court, open daily from 9am and until 2am on weekends.

Austin, Texas

A day spa and med spa in North Burnet offering massage, facials, and injectables, with walk-ins and day passes accepted.

Jackson Hole, Wyoming

Hotel spa inside the Rusty Parrot Lodge in downtown Jackson Hole offering massage, facials and couples treatments with hot tub access, day passes welcome.

Seattle, Washington

A quiet, clothing-optional day spa in Greenwood with soaking pools, saunas and a steam room, women-owned and open to all genders on Wednesdays.

Vail, Colorado

A day spa and recovery club in downtown Vail with hot tub, sauna, steam room, cold plunge and salt lounge, plus day passes and fitness access.

Killarney, Munster

Hotel spa and leisure studio at The Killarney Park with a 20m pool, outdoor jacuzzi, sauna and steam room, open to hotel guests only.

Calistoga, California

A 20-treatment hotel day spa in Santa Rosa with an indoor caldarium plunge pool, eucalyptus steam rooms, and walk-in or reserved day passes for adults 18+.

Idaho City, Idaho

A reservation-only hot springs soak in Idaho City with private tubs, a steam room and a $30 day pass, open five days a week.

Spa, Liège

Thermal baths in the town of Spa, Belgium, fed by natural mineral water, with saunas, hammams and separate textile and naturist relaxation areas.

Rogaška Slatina, Savinjska

Wellness center at Grand Hotel Rogaška in Rogaška Slatina, Slovenia, with pools, saunas and fitness; day pass available by reservation.

Rotorua, Bay of Plenty

A Rotorua day spa built around Ngāti Whakaue hot-springs traditions, centered on a seven-step geothermal Restorative Journey with lakeview thermal pools, mud

Minneapolis, Minnesota

A St. Paul wellness studio in Macalester-Groveland offering infrared sauna, float tanks, salt therapy and cold plunge by reservation, adults-only, day-pass

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.

Asheville, North Carolina

A day spa in a converted barn on Horse Shoe Farm near Asheville, offering massage and body treatments amid farm and mountain surroundings.

New York City, New York

Thermal bath circuit and massages in a restored 1883 Tribeca textile factory, with a skylit tepidarium and candlelit thermal pools; reservation required.

The Hamptons, New York

A membership-based wellness club in Southampton with a stadium-seating sauna, cold plunge pools, treatment suites and group classes.

Santa Fe, New Mexico

A Santa Fe day spa combining yoga, pilates and nia classes with spa treatments, a café and a boutique, open daily 9am–7pm.

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.

Miami, Florida

A large hotel wellness resort on North Beach with a European-style hydrotherapy circuit, cryotherapy, acupuncture and an oceanfront fitness center.