Spas with adults only

Portland, Oregon

A member-run bathhouse in Concordia with a clothing-optional salt-water hot pool, cedar sauna and courtyard, day passes from $18.

Doha

Hotel spa at The Westin Doha with some of the city's largest wet facilities, accessible to hotel guests and members only, no day passes sold.

Atlanta, Georgia

Membership-based medical spa in Buckhead combining aesthetics, massage and facials, and lounge spaces for meditation and recovery.

Los Angeles, California

Women-only Korean day spa in Koreatown, LA with saltwater, mineral and cold pools, a salt room, and walk-in day passes.

Hudson, New York

Adults-only communal thermal baths and steam room in downtown Hudson, NY, with day passes, memberships and treatment-plus-soak packages.

Jackson Hole, Wyoming

A Jackson Hole facility pairing physical therapy, acupuncture and massage with a climbing wall, salt room, infrared sauna and sound healing, open to day-pass

Carmel-by-the-Sea, California

Resort spa at Carmel Valley Ranch with 12 treatment rooms, private terraces, a saltwater pool and infinity hot tub, open to adults by reservation.

Hunter Valley, New South Wales

Large day spa at Chateau Elan in Hunter Valley with 17 treatment rooms, a float tank, outdoor mineral spas and couples' treatments; day passes and walk-ins

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+.

Sun Valley, Idaho

A 50,000-square-foot health club and spa in Ketchum with saltwater pools, a full gym and massage, facial and other spa treatments.

Atlanta, Georgia

A hotel spa and wellness club inside Loews Atlanta Hotel in Midtown, built around hammam, sauna, steam room and a monthly membership rather than drop-in visits.

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.

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.

The Hamptons, New York

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