Spas with private suites

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.

San Diego, California

Adults-only day spa at Mission Bay Resort with massage, facials, Himalayan salt treatments and couples suites; walk-ins and day passes welcome.

Palm Springs, California

Hotel spa at the Renaissance Esmeralda in Indian Wells offering desert-inspired treatments, a recovery lounge, steam rooms and day passes, adults only.

Austin, Texas

Hotel spa at Hotel Viata in West Lake Hills with treatment rooms, a couples suite, pool, sauna, steam room and a day-pass option for amenity access.

Bad Wörishofen, Bavaria

Adults-only thermal baths in Bad Wörishofen with palm-house pools, mineral pools and saunas; day passes available, minimum age 16.

London, England

A Russian-style banya bathhouse in Belgravia offering oak-lined steam rooms, cold plunge pools and leaf-massage rituals, with day passes by reservation only.

Miami, Florida

A 12,000-square-foot hotel spa at Coral Gables' Biltmore, with eucalyptus steam rooms, Himalayan salt saunas and a couples suite; adults-only, reservation

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.

Dallas, Texas

Hotel spa in Uptown Dallas with 12 treatments, couples' rooms, separate men's and women's lounges, sauna, steam room, cold plunge and whirlpool.

Lake Tahoe, California

A 17-room, adults-only hotel spa at Lake Tahoe's Ritz-Carlton with a heated lap pool, sauna and steam room; day pass access requires booking a treatment.

Portland, Oregon

Adults-only hotel spa in downtown Portland with a $50 day pass, infinity pool, sauna, steam room and cold plunge shower, booked in advance only.

Santa Ynez, California

Adults-only resort spa inside Chumash Casino Resort in Santa Ynez with 21 treatments, a mineral pool, cold plunge and couple's suites.

Napa Valley, California

Adults-only hotel spa in Napa Valley with a co-ed thermal circuit of sauna, steam room and cold shower, open daily 10am–6pm; day passes available.

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

Las Vegas, Nevada

An adults-only hotel spa inside Encore Las Vegas with whirlpool, sauna and steam room, open daily for treatments and day passes, walk-ins welcome.

Chicago, Illinois

A 5th-floor day spa inside the Palmer House Hilton in the Loop, built around a hydrotherapy circuit, Vichy shower treatments and a facial called Glow Revival.

Aspen, Colorado

Ski-in/ski-out hotel spa in Aspen with three private treatment suites, 15 treatments, and booking required by phone or email.

Miami, Florida

Hotel spa at The Ritz-Carlton Key Biscayne, Miami, with treatment suites, sauna, steam room and whirlpool, open to hotel guests 18 and up by appointment.

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.

Philadelphia, Pennsylvania

Hotel spa in Center City Philadelphia with a heated indoor saltwater pool, fitness center and day-pass access for non-guests.

Portland, Oregon

A 21-and-up day spa in Portland's Irvington neighborhood built around vinotherapy, with wine-infused baths, massages and Caudalie facials.

Chicago, Illinois

A moderately priced day spa in Chicago's Lakeview neighborhood focused on Chinese-style head and scalp treatments, open to adults 16 and up.

Merano, Trentino-South Tyrol

An adults-only, guests-only longevity retreat and hotel spa in Merano with a medical-led wellness institute and private suite treatments.

Scottsdale, Arizona

Adults-only hotel spa at the Fairmont Scottsdale Princess with a rooftop pool, grotto waterfall pool, sauna, steam room and cold plunge, open daily 6am-7pm.