Spas with reservation required

Koh Samui, Surat Thani

A day spa in Bo Phut, Koh Samui, open daily 9am to 11pm with a sauna and traditional Thai treatments for solo visitors and couples.

Mumbai, Maharashtra

An Ayurveda-based day spa on Marine Drive in Mumbai offering massage, detox and beauty therapies with a relaxation lounge and yoga space.

Minneapolis, Minnesota

A Northeast Minneapolis wellness studio rooted in Traditional Chinese Medicine, offering sauna access by reservation in the Bottineau neighborhood.

Las Vegas, Nevada

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

Ojai, California

A small, independently owned day spa in Ojai offering facials, massage, head spa treatments, infrared sauna and salt therapy.

Park City, Utah

A sauna-and-cold-plunge day spa in Park City with memberships, private group buyouts, and reservation-only access.

Naples, Florida

Day spa in Central Naples with a salt cave for halotherapy, plus massage, facials and yoga classes; walk-ins welcome but reservations recommended.

Nashville, Tennessee

A Gulch studio for infrared sauna and cold plunge sessions in private suites, open daily with reservations required.

Los Angeles, California

A wellness retreat in Westlake's Wilshire corridor offering cold plunge, sauna and movement classes, built around group and community sessions.

Palm Beach, Florida

Salt The Spa is a day spa in Wellington, near Palm Beach, built around a dedicated salt room and newer peptide-therapy treatments.

The Hamptons, New York

Adults-only destination spa and 12-room retreat in Water Mill, offering hydrotherapy, yoga, spa treatments and overnight stays by reservation.

Houston, Texas

A moderate-priced day spa on the 23rd floor of a downtown Houston office tower, open Wednesday through Sunday with a relaxation lounge and sauna.

Carmel-by-the-Sea, California

A hotel spa inside Carmel-by-the-Sea's Hyatt Regency Monterey property, with hydrotherapy, sauna and a relaxation lounge for guests and couples.

Naples, Florida

A hotel spa inside the Inn on Fifth in downtown Naples, open daily for massages, facials, nail services, sauna, steam room and lounge access.

Aachen, North Rhine-Westphalia

A suite hotel in central Aachen where each private room has its own jacuzzi and sauna, booked by the night rather than a day pass.

Pagosa Springs, Colorado

A mobile container-trailer spa in Pagosa Springs offering infrared sauna and cold plunge contrast therapy, adults only, by reservation.

Dallas, Texas

A moderate-priced day spa inside The Crescent complex in Oak Lawn, Dallas, with a sauna and both walk-in and reservation options.

Los Angeles, California

A medical spa in Silver Lake, Los Angeles offering body contouring, massage, hair removal and skin treatments in private suites, open daily 9am to 10pm.

Bad Ragaz, St. Gallen

A resort thermal spa in Bad Ragaz with indoor and outdoor thermal pools and sauna, open daily 7:30am–8pm, reservation required for day passes.

Tepoztlán, Morelos

A day spa and temazcal (traditional Mexican sweat lodge) in Tepoztlán, Morelos, open Wednesday through Sunday with reservations suggested.

Kyoto

Hotel spa on the 2nd floor of Dhawa Yura Kyoto in Higashiyama, offering private-suite treatments by Banyan Tree Academy-trained therapists.

Park City, Utah

Hotel spa at Mayflower Mountain near Deer Valley with massages, facials, a sauna, relaxation lounge and couples treatments; reservations required.

Berkshires, Massachusetts

A Great Barrington wellness studio focused on detox therapies like colon hydrotherapy, infrared sauna and liver flushes, by appointment only.

Hudson Valley, New York

An outdoor spa on the Hudson River in Kingston, NY, with two waterfront barrel saunas and garden massage cabins, reservation required.