Spas with reservation required

Hudson, New York

Adults-only communal thermal baths and steam room in downtown Hudson, NY, with day passes, memberships and treatment-plus-soak packages.

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.

Naples, Florida

Luxury day spa in Central Naples offering massage, facials and combination packages, including a $420 signature ritual, with couples treatments by reservation.

Aspen, Colorado

Adults-only hotel spa at The St. Regis Aspen with Thai-inspired massage, 111Skin facials, an AI robotic massage, and a day pass covering pool, cold plunge, and

Scottsdale, Arizona

Recovery-focused studio in South Scottsdale centered on a cold plunge, hot tub, infrared sauna, compression therapy and red light rooms rather than traditional

Scottsdale, Arizona

A medical spa in central Scottsdale offering 32 treatments—facials, massage, Botox, and a bridal package—alongside a sauna, steam room and thermal pool.

Napa Valley, California

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

Saratoga Springs, New York

Historic 1935 bathhouse in Saratoga Springs offering mineral water soaks and massages in original tubs, reservation only, moderate pricing.

Mexico City, Quintana Roo

A Japanese-style hotel spa in Mexico City's Cuauhtémoc district with tatami suites, outdoor onsen baths and a $2,080 day pass for couples.

Liverpool, New York

A moderate-priced day spa in Liverpool, NY, offering 20 massage-focused treatments plus sauna, steam, cold plunge and thermal pools, open daily 10am–8pm.

Cockeysville, Maryland

A Cockeysville medical day spa blending clinical massage, sauna, steam and thermal pool with reiki, coaching and corrective exercise for chronic pain and

Scottsdale, Arizona

Hotel spa at the Inn at Eagle Mountain in Fountain Hills with sauna, steam room, pools and a $69 60-minute massage as its signature treatment.

Sedona, Arizona

A moderately priced day spa in Sedona with outdoor gardens, a hot tub and fountains, known for its Prickly Pear Pomegranate body treatment.

Las Vegas, Nevada

Adults-only hotel spa inside Westgate Las Vegas offering massages, facials, salon services, sauna, steam room and a thermal pool, open daily 9am-6pm.

Asheville, North Carolina

A Japanese-inspired destination spa on a mountainside outside downtown Asheville, built around private outdoor salt hydrotherapy tubs and massage.

Sierraville, California

A non-profit hot springs retreat near Lake Tahoe with natural spring pools, reservation-only day and evening soaks, camping and rooms, closed Mondays and

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.

Seattle, Washington

A reservation-only social wellness sauna spa in Renton (serving the Seattle area) with a thermal pool, cold plunge, sauna and steam room, day passes from $75.

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.

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.

Boca Raton, Florida

Hotel spa at The Boca Raton with 44 treatment rooms, a spa pool and waterfall whirlpools, open to resort guests, club members and day-pass visitors by

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.