Spas with reservation required

Cotswolds, England

A wood-fired riverside sauna at Whichford Mill in the Cotswolds, with a cold-plunge bath, river dipping, and both private and communal sessions.

Naples, Florida

A one-on-one day spa inside Salon by JC on 5th Avenue South in Old Naples, offering facials, massages and body treatments by appointment.

New York City, New York

Thermal bath circuit and massages in a restored 1883 Tribeca textile factory, with a skylit tepidarium and candlelit thermal pools; reservation required.

Coorg, Karnataka

Riverside resort spa in Coorg with private bungalows, a pool, and spa treatments along the Kaveri River; booking required.

San Diego, California

Full-service day spa on the 3rd floor of AquaVie Fitness + Wellness Club in downtown San Diego, offering massage, facials and multi-step body rituals by

Rishikesh, Uttarakhand

An upscale riverside resort 18 km outside Rishikesh with an in-house spa, yoga studio and restaurant, open only to overnight guests by reservation.

Boston, Massachusetts

A Moroccan-style hammam on Route 1 in Peabody offering steam, sauna and exfoliation treatments for adults and couples, reservation only.

San Diego, California

A day spa in University City, San Diego, open since the late 1990s, offering facials, massage and lymphatic drainage with a monthly membership option.

Los Angeles, California

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

Vail, Colorado

Medical spa in Vail offering facials, skin therapies, IV drips and sports recovery treatments, with walk-ins welcome but reservations recommended.

Naples, Florida

Sole-practitioner day spa in Naples, FL offering massage, cupping, facials and a plumbed Japanese-style head spa, with private treatment suites.

Los Angeles, California

A day spa on La Brea Avenue near the Fairfax area of Los Angeles offering massages, facials and hydrotherapy, with reservations recommended.

Milwaukee, Wisconsin

East Town Spa in Milwaukee's Juneau Town combines a full-service salon and med spa with a thermal circuit of sauna, steam, pools and cold plunge.

Aspen, Colorado

Adults-only day spa in downtown Aspen focused on facials, microdermabrasion, micro-needling and Block Therapy fascia work by appointment.

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.

Antalya

A Turkish hammam and day spa in Konyaaltı, Antalya, offering steam baths, scrub-and-foam treatments, Doctor Fish, and massage therapy.

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.

Key West, Florida

A day spa just off Duval Street in Key West offering massage, facials, waxing and a Vichy shower, with walk-ins possible but reservations preferred.

Tucson, Arizona

Day spa in Tucson's La Encantada shopping center with a thermal circuit of sauna, steam room, cold plunge and soaking pools.

Mérida, Yucatán

Resort spa on the grounds of Hacienda Xcanatun near Mérida, with a pavilion over a pond offering Asian-style massages and facials by reservation.

Zanzibar

A dedicated hammam in Stone Town offering a traditional steam, scrub and oil-massage ritual, open daily with reservations required.

Miami, Florida

A beer-bath spa in Little Haiti where you soak in a cedar tub infused with hop ingredients and sip a cold beer on tap.

Hudson Valley, New York

A second-floor day spa on Main Street in Goshen, NY, specializing in four customizable facials priced from $175 to $225.