Spas with reservation required

Palm Springs, California

Adults-only hotel spa at Tommy Bahama Miramonte in Indian Wells with 15 treatments, eucalyptus steam rooms, a hydrotherapy jacuzzi and saltwater pool.

Calistoga, California

Spa Talisa is the adults-only spa at the Four Seasons Resort Napa Valley in Calistoga, with vineyard-view gardens, barrel saunas and a sunken whirlpool for

Napa Valley, California

Adults-only resort spa built into a wine cave in Napa, with a vineyard-view pool, sauna, steam room and hot tub; reservations required.

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.

Atami, Shizuoka

Hotel spa inside Fufu Atami using Sisley's plant-based treatments, with sauna, steam and thermal pool access for adults only.

Los Angeles, California

Korean-style day spa in Koreatown with detox rooms, body scrubs, gender-specific hours and on-site validated parking.

Naples, Florida

Upscale day spa in Naples offering infrared sauna, massage, facials and foot detox, with a $230 signature massage and couples packages.

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.

Los Cabos, Baja California Sur

A hotel spa at Corazón Cabo Resort offering massages, facials and a hydrotherapy circuit with sauna, steam room and hot tub, no day passes sold.

Kissimmee, Florida

A hotel spa at Margaritaville Resort Orlando in Kissimmee with massages, facials and a Himalayan salt room; open daily, walk-ins welcome.

San Francisco, California

A Thai massage day spa in SOMA's Design District offering herbal compress treatments, a dry sauna, couples rooms and free parking.

Palm Springs, California

Hotel spa at Agua Caliente Rancho Mirage with day passes for the sauna, steam room, salt rooms and private spa pool.

Las Vegas, Nevada

A day spa inside Tuscany Suites & Casino in Las Vegas offering massage, facials and body treatments alongside sauna, steam and cold plunge access.

Palm Beach, Florida

A Palm Beach Gardens studio offering 60-minute private-suite sessions combining infrared sauna, cold plunge and vitamin-c shower.

Charleston, South Carolina

Private contrast-therapy suites with infrared sauna, cold plunge and vitamin C shower in West Ashley, Charleston, by reservation.

Bad Wörishofen, Bavaria

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

Philadelphia, Pennsylvania

Day spa in Cherry Hill Township near Philadelphia offering massage, head spa scalp treatments and couples sessions, open daily 9:30am to 9:30pm.

Tbilisi

A medical spa in Old Tbilisi built around natural sulfur-mineral water and volcanic mud, operating since 1938, open daily 10am–9pm.

Chianciano Terme, Tuscany

Thermal day spa in Chianciano Terme offering day passes, couples massages and a wellness-food menu, closed Thursdays and Wednesdays.

Dallas, Texas

A reservation-only day spa in Preston Hollow offering massage, body contouring, lymphatic drainage and infrared sauna sessions.

Houston, Texas

Thai Massage and Day Spa is a moderate-priced day spa in Houston's Mid West area offering Thai massage, facials, body treatments and couples sessions.

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

New York City, New York

An Upper East Side day spa built around couples' treatments—massage, sauna and a signature rose-petal bath—by reservation only.