Spas with upscale

Carmel-by-the-Sea, California

Upscale day spa in Carmel-by-the-Sea's Golden Rectangle with sauna, steam, cold plunge and thermal pools, open daily from 6:30am.

New York City, New York

Korean-style day spa in Edgewater, NJ, with saunas, thermal pools and an infinity pool, open daily 9am–9:30pm, day passes for walk-ins.

Sonoma, California

A boutique day spa in downtown Sonoma centered on infrared sauna and cold plunge drop-ins, plus massage, red light and PEMF therapy.

Sopot, Pomerania

A medical resort spa in Sopot built around local brine and mud treatments, open to hotel guests by reservation rather than day visitors.

Austin, Texas

Adults-only hotel spa at the Fairmont Austin with nine treatment rooms, a hydrotherapy circuit, sauna and cold plunge, open daily with day passes available.

Dallas, Texas

Hotel spa inside The Adolphus in downtown Dallas, with six treatment rooms, a couple's suite and a 22-item menu of massages, facials and body treatments.

Las Vegas, Nevada

Spa Aquae is JW Marriott Las Vegas Resort & Spa's day spa in Summerlin, with 18 treatments, couples massages and a steam room, open daily 8am-7pm.

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.

Chamonix, Auvergne-Rhône-Alpes

Hotel spa at Heliopic Chamonix with an ice cave, cold-water well, hammams, sauna and a 15m pool facing the Mont Blanc massif, open to day visitors who book a

Aix-les-Bains, Auvergne-Rhône-Alpes

An upscale day spa inside Hotel Le Riviera in Aix-les-Bains, with pools, saunas, a hammam and eight treatment rooms open to walk-ins.

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.

Orlando, Florida

Upscale day spa at Bella Collina private club near Orlando, open Tuesday–Sunday by appointment, with massages, facials and couples suites.

San Diego, California

Adults-only hotel spa at Kona Kai Resort on Shelter Island with six treatment rooms, a couples' suite and day-pass access for non-guests.

Jackson Hole, Wyoming

Resort spa at Teton Village with pools, soaking tubs, a rooftop hot tub, and facials built for Jackson Hole's dry alpine air.

Quebec City, Quebec

A riverside Nordic spa in Old Quebec with an infinity pool, salt-water floating bath and thermal baths along the St. Lawrence, open daily 9am-10pm.

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

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.

Calistoga, California

Hotel spa in downtown Healdsburg with a garden patio, jacuzzi and pool access, open daily 9am-5pm for guests and day visitors.

Scottsdale, Arizona

Resort spa at Camelback Inn in Scottsdale with 20 treatment rooms, a thermal circuit and day-pass access open to non-guests.

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.

Nashville, Tennessee

A hotel spa in downtown Nashville with six treatment rooms, a rooftop infinity pool, and day passes open to non-guests.