Spas with reservation required

Castle Rock, Colorado

A small day spa studio in Castle Rock offering massage, facials, waxing, lashes, brows and permanent cosmetics by appointment.

Seattle, Washington

A themed-suite day spa in Seattle's SODO district offering massages, facials, couples packages and a few overnight suites.

Elkridge, Maryland

A halotherapy day spa in West Elkridge, near Baltimore, built around a salt cave, massage rooms and a yoga studio, aimed at solo adult visitors.

Springboro, Ohio

A wellness center in Springboro, Ohio built around a natural salt cave, with energy healing, sound baths and metaphysical classes for individuals or groups.

Los Angeles, California

Day spa in a Montebello strip mall plaza offering facials, massages and body treatments, open daily with walk-ins accepted.

South Jordan, Utah

A day spa and wellness center in South Jordan, Utah, with a salt room, infrared sauna, cold plunge, float therapy and a yoga studio.

Ubud, Bali

An adults-only wellness retreat on Ubud's Ayung River offering multi-day healing programmes, thermal circuits and plant-based cuisine by reservation only.

Nashville, Tennessee

Float Horizen is a day spa in Nashville's East End offering sensory-deprivation float tanks, infrared sauna, massage and sound meditation sessions.

San Diego, California

A Clairemont wellness studio in San Diego pairing acupuncture and bodywork with an infrared sauna and a Himalayan salt room for classes.

Transylvania County, North Carolina

All-inclusive multi-night wellness retreat in Pisgah Forest, NC, combining fitness classes, spa treatments, guided hikes and farm-to-table meals in private

Orlando, Florida

A full-service salon and spa in Orlando pairing hair, skincare and waxing services with a monthly membership plan for mix-and-match treatments.

Charlotte, North Carolina

A moderate-priced day spa in Charlotte's SouthPark area with a sauna, steam room and thermal pool alongside massage, facial and body-treatment menus.

Carmichael, California

A single-room salt cave in a Carmichael strip mall offering 45-minute salt therapy sessions for relaxation and respiratory relief.

San Francisco, California

A reservation-only day spa on El Camino Real in San Bruno specializing in head spa therapy, scalp care and lash services for adults.

North Royalton, Ohio

A North Royalton day spa built around a salt room and sauna, with adults-only halotherapy sessions on a walk-in or reserved basis.

Las Vegas, Nevada

Float tank, massage and salt therapy spot in Peccole Ranch, Las Vegas, open daily with walk-ins accepted alongside bookings.

Des Peres, Missouri

A moderate-priced day spa in Des Peres, just west of St. Louis, open six days a week with a relaxation lounge and treatments geared toward couples and adults.

Texas Hill Country, Texas

A medical spa on San Antonio's Far West Side offering massage, facials, injectables and laser hair removal, open weekdays and Saturday mornings.