Spas with adults only

San Francisco, California

Oakland float and sauna studio near Grand Lake with private float tanks, infrared sauna cocoons and cryotherapy, open daily 11am-8:30pm.

Sedona, Arizona

Day spa in Sedona with eucalyptus steam rooms, saunas, jacuzzi and a fitness center, offering day passes and memberships for walk-in guests.

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

Elkridge, Maryland

A halotherapy day spa in West Elkridge, near Baltimore, built around a salt cave, massage rooms and a yoga studio, aimed at solo adult visitors.

Palm Springs, California

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

Sonoma, California

Hotel spa at The Lodge at Sonoma with an outdoor terrace, soaking pool, plunge pool and barrel sauna, open daily 9am-5pm, adults-only, reservation required.

Carmel, Indiana

A no-frills contrast therapy studio in Carmel, Indiana, built around a 30-minute sauna-and-cold-plunge circuit for solo visitors.

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.

Ubud, Bali

An adults-only wellness retreat on Ubud's Ayung River offering multi-day healing programmes, thermal circuits and plant-based cuisine by reservation only.

Colorado Springs, Colorado

An adults-only medical day spa in Colorado Springs offering constitutional hydrotherapy, infrared sauna and homeopathy by appointment.

San Diego, California

A Clairemont wellness studio in San Diego pairing acupuncture and bodywork with an infrared sauna and a Himalayan salt room for classes.

Transylvania County, North Carolina

All-inclusive multi-night wellness retreat in Pisgah Forest, NC, combining fitness classes, spa treatments, guided hikes and farm-to-table meals in private

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.

Carmichael, California

A single-room salt cave in a Carmichael strip mall offering 45-minute salt therapy sessions for relaxation and respiratory relief.

Scottsdale, Arizona

Adults-only resort spa in Fountain Hills with sauna, steam room and outdoor pools, offering day passes and an amethyst facial as its signature treatment.

San Francisco, California

Adults-only hotel spa in Sausalito, California, offering day passes alongside yoga and a restaurant on site.

South Haven, Michigan

An adults-only glamping resort and pool club at South Haven Country Club with a day-pass spa area featuring a pool, sauna and relaxation lounge.

Scottsdale, Arizona

Adults-only resort spa in Scottsdale with sauna, steam, cold plunge and thermal pools, open only to hotel guests.

San Diego, California

A 21-and-over hotel spa in San Diego's Gaslamp Quarter with sauna, steam room, cold plunge and thermal pools, open to hotel guests only.

North Royalton, Ohio

A North Royalton day spa built around a salt room and sauna, with adults-only halotherapy sessions on a walk-in or reserved basis.

Albuquerque, New Mexico

Hotel Zazz is an adults-only boutique hotel in Albuquerque's Nob Hill district with an on-site spa, heated pool and speakeasy lounge.

Houston, Texas

A rooftop pool, cabanas, fitness center and yoga room at this Houston hotel are open to non-guests via a $60 adults-only day pass.

Miami, Florida

A hotel spa in downtown Miami with a day pass covering sauna, steam, cold plunge and thermal pools, plus 13 treatments on the menu.

San Juan

Adults-only hotel spa inside La Concha Resort in Condado, San Juan, offering couples massages and a small treatment menu for guests 18 and up.