Spas with relaxation lounge

London, England

Thermal bathhouse near Covent Garden in a former J.M. Barrie house, offering multi-temperature pools, massages and couples treatments by reservation.

Toronto, Ontario

A reservation-only thermal bath circuit in a 1912 Edwardian building in Toronto, with eight pools, a dry sauna, steam room and massage treatments.

Las Vegas, Nevada

Adults-only hotel spa inside ARIA Resort & Casino in Las Vegas, with sauna, steam room, thermal pools and cold plunge, open to hotel guests 18 and up.

Amsterdam, North Holland

A day spa inside a former bank vault in central Amsterdam, with pool, whirlpool and a canal-view gym; adults-only, day pass by reservation.

Dallas, Texas

Hotel spa inside W Dallas in Victory Park offering massages, facials, body treatments and separate men's and women's lounges, open to day-pass guests.

Santa Fe, New Mexico

A small medical spa in Santa Fe focused on advanced facials, skin rejuvenation and massage, by reservation.

Barcelona, Catalonia

Adults-only thermal baths in a converted 18th-century building near Barcelona's Born market, with soaking pools, massages and couples rituals.

Bagno Vignoni, Tuscany

Hotel spa in a 15th-century Bagno Vignoni palazzo with a thermal pool fed by the village's natural hot springs, open to day visitors.

Amman

A hotel hammam in Tla al-Ali, Amman, with marble bathing halls, a hot pool, sauna and Jacuzzi, offering about 20 treatments from a basic scrub to a $120

Chicago, Illinois

Reservation-only day spa in Chicago's River North/Goose Island area with massage, facials and body treatments, plus a chakana-shaped tented relaxation room.

Houston, Texas

Island-themed day spa in Montrose offering massage and body treatments by appointment only, with no walk-in day pass.

Bad Gastein, Salzburg

Thermal baths in Bad Hofgastein with indoor/outdoor pools, bathing lakes, slides, saunas and a sports medicine center, open daily year-round.

Marbella, Andalusia

Hotel day spa at Amàre Marbella with a hydrotherapy circuit, facial treatments, massages and couples options, open daily 11am-7pm.

Sonoma, California

A Sonoma medical day spa run by a 25-year skincare specialist, offering non-toxic facials, microcurrent and micro-channeling treatments up to $350.

Chiang Mai

Hotel spa at Anantara Chiang Mai with steam rooms, sauna and couples' suites, built around the signature Lanna Ritual massage overlooking the riverfront pool.

Nashville, Tennessee

A Midtown Nashville spa inside Sola Salons that does one thing: head spa treatments combining scalp massage, warm water, steam and a finishing blowout.

Längenfeld, Tyrol

A large thermal bath and 4-star hotel spa in the Ötztal valley near Längenfeld, with indoor-outdoor pools, a sauna garden and a dedicated kids' water world.

Singapore

Garden-set day spa inside Bishan Park 2 with 12 treatment rooms, outdoor baths, massages and facials using Elemis and Skinceuticals products.

Daylesford, Victoria

A rammed-earth house on 80 hectares near Daylesford, rented whole for up to 10 adults, with in-room massage and a two-night minimum stay.

Sydney, New South Wales

Reservation-only Korean bathhouse in Paddington, Sydney, with herbal baths, a steam room and the signature Korean Body Scrub, closed Tuesdays.

Asheville, North Carolina

A therapist-owned day spa near downtown Asheville offering massage, bodywork, a private sauna and foot soaks by appointment, with free parking.

Asheville, North Carolina

A downtown Asheville salt cave with Himalayan salt walls, a hammam steam bath and massage rooms for solo visitors and couples, reservation-based.

Aspen, Colorado

A reservation-only Aspen studio offering private sound, energy and subconscious-journey sessions instead of classic spa treatments.

Hot Springs, Arkansas

Adults-only hotel spa at Oaklawn Resort in Hot Springs with vitality pools, heated loungers, needle showers and treatment-based access only.