Spas with reservation required

Kissimmee, Florida

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

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.

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.

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

Port Douglas, Queensland

Ayurvedic-style massage and bathhouse studio in Port Douglas offering couples treatments, yoga and reformer Pilates, bookings required with no walk-ins.

Portland, Oregon

An 18-and-up, clothing-optional spa in Portland's Kerns neighborhood with a salt hot tub, sauna, steam room and cold plunge, reservation required.

Chicago, Illinois

Luxury hotel spa in River North, Chicago, with an indoor pool, steam room and lounges, open to both hotel guests and outside bookings by reservation.

Los Angeles, California

A Silver Lake day spa with 20 treatments, Thai massage, acupuncture and a salt-infused infrared sauna, open daily 10am-9pm.

Dallas, Texas

Hotel spa in Uptown Dallas with 12 treatments, couples' rooms, separate men's and women's lounges, sauna, steam room, cold plunge and whirlpool.

Marana, Arizona

Adults-only hotel spa at Dove Mountain Resort in Marana with desert-themed treatments, an infinity-edge pool, sauna and steam room; facility access comes with

Lake Tahoe, California

A 17-room, adults-only hotel spa at Lake Tahoe's Ritz-Carlton with a heated lap pool, sauna and steam room; day pass access requires booking a treatment.

Portland, Oregon

Adults-only hotel spa in downtown Portland with a $50 day pass, infinity pool, sauna, steam room and cold plunge shower, booked in advance only.

Las Vegas, Nevada

A Summerlin day spa centered on Himalayan salt rooms, plus massage, facials and Reiki, open daily 10am-7pm.

Asheville, North Carolina

An appointment-only Asheville spa built around a Himalayan salt cave, booking private salt therapy and massage sessions for up to nine guests at a time.

BAITING HOLLO, New York

A 10,000-square-foot spa and hair salon in Baiting Hollow with couple's suites, saunas and steam rooms, part of the East Wind resort on Long Island.

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.

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.

Boston, Massachusetts

Adults-only hotel spa at Encore Boston Harbor in Everett with separate men's and women's heat and water facilities, booked by appointment.

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.

San Diego, California

Adults-only hotel spa in Carmel Valley with a hydrotherapy circuit, two fireplace lounges, and a $100 day pass covering pools and fitness facilities.

Austin, Texas

A hotel spa in downtown Austin with six treatments, a salt-wall relaxation lounge, eucalyptus steam rooms and a fitness center, open daily by reservation.

New York City, New York

A 30-treatment luxury hotel spa in Lower Manhattan with a lap pool, steam rooms and the German GREEN PEEL facial as its signature service.