Spas with upscale

French Riviera, Provence-Alpes-Côte d'Azur

Hotel spa inside Nice's Le Negresco with hammam, sauna and fitness center; outside guests must book a 90-minute treatment to use the wet areas.

Atlanta, Georgia

Day spa and med spa in Brookhaven Village offering massages, facials and injectables like Botox and filler, open daily 9am-9pm by reservation.

Mexico City

Upscale adult-only day spa in Roma Norte with a six-treatment menu built around massage, skin care and one of the city's more elaborate hydrotherapy circuits.

Hobart, Tasmania

Upscale day spa in central Hobart with infrared sauna, magnesium spa, ice bath and in-house naturopathy, open daily except Mondays with walk-ins and day passes.

Denver, Colorado

A Littleton day spa centered on private suites with beer and wine baths, infrared sauna, zero-gravity massage and a self-pour taproom.

Santa Fe, New Mexico

A 77-acre hot springs resort outside Santa Fe with spring-fed thermal pools, day-pass soaking packages from $175, and overnight lodging.

Nashville, Tennessee

A full-service hotel spa on the fourth floor of Omni Nashville, downtown, offering massages, facials, salon services and a rooftop pool, open to non-guests via

Edinburgh, Scotland

One Spa is an adults-only day spa in Edinburgh's city centre with a rooftop Hydropool, thermal suite and day-pass access.

Occidental, California

Day spa in Freestone, Sonoma County, known for its Cedar Enzyme Bath and Japanese gardens, open daily with walk-ins welcome.

Scottsdale, Arizona

Adults-only resort spa at the Andaz Scottsdale with treatment suites, a private pool, fitness center and cabana bookings, day pass available.

Shibu Onsen, Nagano

Reservation-only private hot spring and sauna suites at a Nagano brewery complex, built around a craft beer bathing plan for two to four guests.

Park City, Utah

A 14-room hotel spa at Westgate Park City Resort with a waterfall, sauna, steam room and thermal pools, open daily 9:30am-6:30pm.

Houston, Texas

A Central Business District day spa with a rooftop pool, offering facials, massages and body treatments, open daily with walk-in access.

Lombok, West Nusa Tenggara

A hotel-guest-only wellness room at Rascals in Kuta, Lombok, with a traditional sauna, dual ice baths and a magnesium pool, open daily 8am–9:30pm.

Denver, Colorado

A 14,000-square-foot hotel spa inside Gaylord Rockies in Aurora, offering massages, facials, body treatments and a couples room, adults only.

Boston, Massachusetts

A Seaport social wellness club in Boston offering saunas, ice baths, IV therapy, red light and HBOT sessions, with reservations required and no membership

Philadelphia, Pennsylvania

A head spa in Queen Village, Philadelphia, focused on scalp and hair treatments, with private suites and a $300 signature service.

Nashville, Tennessee

A Midtown Nashville wellness studio built around cryotherapy, infrared sauna, red light therapy, IV drips and recovery treatments, run mostly through monthly

Scottsdale, Arizona

A hotel spa at JW Marriott Desert Ridge with sauna, steam rooms, a sanctuary pool, bistro and salon, open to day-pass guests as well as hotel guests.

Nashville, Tennessee

Day spa and medical spa on the third floor of The Westin Nashville downtown, with nine treatment rooms, a dry cedar sauna, steam showers and walk-in access to

Park City, Utah

Hotel spa in Canyons Village at the Grand Summit with sauna, steam room, three whirlpools and a 22-treatment menu including ski-recovery massages.

Napa Valley, California

Hotel day spa atop the Archer in downtown Napa with a water deck, fitness studio access and treatment rooms; reservations required.

Jackson Hole, Wyoming

A hotel spa at Rustic Inn Creekside Resort in Jackson Hole with dry sauna, eucalyptus steam room, outdoor pool and hot tub, open to overnight guests only.

Sirmione, Lombardy

A lakeside thermal spa in Sirmione with indoor and outdoor pools fed by sulphurous spring water, a vascular circuit, saunas, and a day-pass option.