Spas with reservation required

Las Vegas, Nevada

Adults-only hotel spa at Resorts World Las Vegas with a six-pool hydrotherapy circuit, salt room, and a themed Aufguss sauna show on weekends.

Las Vegas, Nevada

Hotel spa inside Hilton Grand Vacations on the Las Vegas Strip, open to non-guests via day pass or booked treatment, minimum age 16.

Kissimmee, Florida

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

Charleston, South Carolina

A hotel spa at Charleston Harbor Resort's Beach Club offering individual and couples treatments with organic Naturopathica products; open to the public, no

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.

Tucson, Arizona

Six-room hotel spa at Hacienda del Sol in Tucson, open daily 9-6, taking both resort guests and local walk-ins for massages, facials and body treatments.

Calistoga, California

A 20-treatment hotel day spa in Santa Rosa with an indoor caldarium plunge pool, eucalyptus steam rooms, and walk-in or reserved day passes for adults 18+.

Miami, Florida

Hotel spa inside Trump National Doral with 42 treatments, couples massages, sauna, steam room, cold plunge and jacuzzi, open daily 9am-7pm.

Scottsdale, Arizona

Hotel spa inside Hotel Solaya in South Scottsdale built around Tod Miller's proprietary BodyWalking compression technique, with four treatments and a $335

Dallas, Texas

Hotel ZaZa's spa in Oak Lawn offers massage and skincare treatments with valet parking and pool access, but no standalone day pass.

Houston, Texas

A hotel spa inside The Laura Hotel in downtown Houston offering massage, facial and nail treatments for solo visitors, couples and groups.

Prague

A beer-spa and wellness venue in Prague's Nové Město district offering beer-bath tubs, massages, and a saunarium, open daily from 11am to 11pm.

San Francisco, California

A moderately priced fitness-club spa in downtown San Francisco offering bodywork, skincare and specialty treatments with reservations required.