Spas with adults only

Boston, Massachusetts

A Moroccan-style hammam on Route 1 in Peabody offering steam, sauna and exfoliation treatments for adults and couples, reservation only.

San Francisco, California

Hotel spa on the 8th floor of 1 Hotel San Francisco with rooftop stone soaking tubs and Bamford skincare treatments, open daily for day visitors.

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.

Zanzibar

A dedicated hammam in Stone Town offering a traditional steam, scrub and oil-massage ritual, open daily with reservations required.

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.

Philadelphia, Pennsylvania

A medical spa in Philadelphia's Northern Liberties/Fishtown area offering facials, laser treatments, injectables, massage and bridal prep packages.

Milan, Lombardy

Adults-only day spa in a Liberty-style building near Milan's Parco Sempione, with thermal pools, saunas, steam room and a hydrotherapy circuit.

Portland, Oregon

Day spa and natural medicine clinic in NW Portland's Slabtown with sauna, hydrotherapy, massage, acupuncture and a vegan café on site.

Orlando, Florida

A 10,000-square-foot hotel spa at Westgate Lakes Resort in Orlando with massages, facials, sauna, steam room and a fitness studio, open daily.

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

San Diego, California

A rooftop hotel spa in San Diego's Gaslamp Quarter offering treatments and a 24/7 fitness center, open to hotel guests and day-pass visitors.

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.

Vichy, Auvergne-Rhône-Alpes

Adults-only thermal baths in Vichy using the town's mineral spring water, with a hydrotherapy circuit and thermal pool, booking 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.

Tucson, Arizona

Day spa near Swan Way Park in Tucson with a cedar hot tub, cold plunge, infrared sauna and massage, bookable by reservation for adults only.

Vals, Grisons

Peter Zumthor's quartzite thermal baths in Vals, fed by a 30°C mineral spring, open to day visitors as well as hotel guests.

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.

Portland, Oregon

A walk-in bathhouse in Portland's Hazelwood neighborhood with a sauna, open daily from 10 a.m. to 10 p.m. for adults only.

Portland, Oregon

Adults-only hotel and thermal springs on NE Alberta St in Portland, with vitality pools, a day-pass option, and spa treatments.

Carson, Washington

A clothing-optional, adults-only mineral hot springs bathhouse in Carson, Washington, with a $12 day pass and a $30 bath-and-wrap treatment.

Jerusalem, Jerusalem District

An adults-only resort spa in the Judean Hills outside Jerusalem, with indoor and outdoor pools, a hammam and a day-pass option.