Spas with groups

Atlanta, Georgia

A Midtown Atlanta hotel day spa with massage, facials, nail services, a steam room and a lounge serving mimosas and spa bites.

Băile Felix, Bihor

Strand Apollo-Felix is a year-round thermal pool complex in Băile Felix, Romania, with indoor and outdoor pools open daily from 8am to 8pm.

Barcelona, Catalonia

Rooftop day spa at Casa Bonay hotel in Eixample with dry sauna, hammam, ice bath and a Japanese ofuro, booked by small-group circuit or free use.

Asheville, North Carolina

Resort spa on an 85-acre Hendersonville farm near Asheville, with massage treatments in a converted horse barn, day passes, and a pool with sauna, steam and

Asan, South Chungcheong

Hot springs resort spa in Asan with thermal pools, sauna and a relaxation lounge, open daily on a walk-in day-pass basis.

Băile Felix, Bihor

A thermal baths complex in Băile Felix with outdoor and indoor pools, open daily with walk-in access and no membership required.

Santa Cruz, California

A hotel spa on a 300-acre Santa Cruz hilltop with Monterey Bay views, outdoor baths and a relaxation lounge, open only to resort guests.

Pai, Mae Hong Son

A walk-in herbal sauna and cold-plunge spot in Pai with a restaurant and lounge attached, open daily 8am-10pm.

Kapaau, Hawaii

An oceanfront eco-boutique hotel and wellness retreat on Hawaii Island's North Kohala coast, open to overnight guests only, not day visitors.

Thermopolis, Wyoming

Free public bathhouse in Thermopolis, Wyoming, with indoor and outdoor mineral soaking pools held at 104°F, open seven days a week.

Palm Springs, California

A 10-room mineral hot springs hotel in Desert Hot Springs near Palm Springs, offering day passes to its 120°F spring-fed pools, sauna and massage rooms.

Karjalohja, Uusimaa

Lakeside resort spa on Lohjanjärvi in Karjalohja, about an hour from Helsinki, with a day pass, thermal pool, salt room and restaurant.

Park City, Utah

A sauna-and-cold-plunge day spa in Park City with memberships, private group buyouts, and reservation-only access.

Berkshires, Massachusetts

A lakeside resort in Egremont with a seasonal pool and sauna for overnight guests only; no day passes and no spa treatments on offer.

Los Angeles, California

A wellness retreat in Westlake's Wilshire corridor offering cold plunge, sauna and movement classes, built around group and community sessions.

Carmel-by-the-Sea, California

A hotel spa inside Carmel-by-the-Sea's Hyatt Regency Monterey property, with hydrotherapy, sauna and a relaxation lounge for guests and couples.

Naples, Florida

A hotel spa inside the Inn on Fifth in downtown Naples, open daily for massages, facials, nail services, sauna, steam room and lounge access.

Arima Onsen, Hyogo

Hotel spa in Arima Onsen with Arima's rare iron-rich "ginsen" waters, outdoor baths, sauna and jacuzzi, run as an all-inclusive overnight stay.

Prague

A beer-spa and wellness venue in Prague's Nové Město district offering beer-bath tubs, massages, and a saunarium, open daily from 11am to 11pm.

Miami, Florida

A hotel spa at Eden Roc Miami Beach in Mid-Beach with sauna, steam room, cold plunge and thermal circuits, open to resort guests only.

Catskills, New York

A Catskills retreat center with a Tibetan-style spa offering sauna, steam, pools and cold plunge, built around overnight stays and group programs.

Kyle, Texas

A 88-acre Hill Country resort near Kyle and Wimberley with overnight rooms, a garden spa, pool, hot tubs and day-pass access by reservation.

Miami, Florida

A hotel spa inside the Four Seasons in Brickell, reserved for hotel guests, with rooftop pool and bay views as part of the stay.

Pai, Mae Hong Son

Affordable day spa near Pai's Wednesday Market open daily except Monday from 3pm to 9pm, with walk-in access and a sauna.