Spas with reservation required

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.

Santa Barbara, California

A downtown Santa Barbara day spa built around a private infrared sauna, salt room, cold plunge and a sound-and-light meditation pod, booked by appointment.

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.

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.

Santa Barbara, California

A small downtown Santa Barbara day spa off State Street offering waxing, facials, massage and skin treatments, with online booking required.

Lake Tahoe, California

Adults-only hotel spa at Edgewood Tahoe with gemstone massage rituals, an oxygen bar, and treatment-only access to the facility.

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.

Philadelphia, Pennsylvania

A small reservation-only day spa in Center City East Philadelphia offering facials, massage, and lash and brow services.

Piešťany, Trnava Region

Spa Irma on Piešťany's spa island offers historic mud and mirror thermal pools, a hydrotherapy circuit and a 60-treatment medical spa menu, adults only.

San Francisco, California

Day spa on the 17th floor near Union Square offering massage-focused treatments, open daily 10am-8pm with walk-ins accepted.

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.

Seattle, Washington

Hotel spa inside the Hyatt Regency Lake Washington in Renton, offering massages, facials and body treatments alongside pool, hot tub and steam room 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.

Hudson, New York

A Hudson, NY day spa and Aveda salon offering hair, facials and massage, with a $130 Japanese Head Spa as its signature treatment.

Sedona, Arizona

Customizable wellness retreat center in Sedona offering day packages, private retreats and bodywork sessions by appointment, open daily 9am-7pm.

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.

Frisco, Texas

An Ayurvedic wellness center in Frisco offering oil massage, shirodhara, dosha consultations and detox packages, led by practitioner Ritu Bhalla.

Bad Wörishofen, Bavaria

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

Taos, New Mexico

A one-esthetician skincare studio in Taos offering organic facials, peels and waxing, with a 90-minute signature facial-plus-massage treatment at $145.