Spas with reservation required

Carmel-by-the-Sea, California

Small massage studio on 8th Avenue in Carmel-by-the-Sea offering six treatments including couples massage, open daily 9am-7pm.

Seattle, Washington

A med spa and beauty bar inside Seattle's Fairmont Olympic Hotel, open daily with facials, injectables, massage and nail services by appointment.

Palm Beach, Florida

A Juno Beach day spa with sauna, steam room and pool, offering massages, facials and couples treatments since 2008.

Nipomo, California

A Nipomo day spa at the Monarch Club where massages and facials come with access to a garden hot tub, eucalyptus steam room and lounge.

Washington, D.C., District of Columbia

Hotel spa at Pendry Washington DC - The Wharf with eucalyptus steam rooms, a heated whirlpool and an outdoor terrace pool, open daily 10am-6pm.

Santa Fe, New Mexico

A Japanese-style hot tub resort spa in Santa Fe with 13 treatments, on-site dining, and reservation-only access for couples or solo visits.

Philadelphia, Pennsylvania

Hotel spa on the third floor of The Rittenhouse overlooking Rittenhouse Square, with massage, facials, body treatments and a salon.

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.

Orlando, Florida

Hotel spa at the Rosen Centre on International Drive in Orlando, offering massages, facials, nail care and access to a steam room, pool and fitness center.

Sonoma, California

Hotel spa at The Lodge at Sonoma with an outdoor terrace, soaking pool, plunge pool and barrel sauna, open daily 9am-5pm, adults-only, reservation required.

Asheville, North Carolina

A holistic wellness center in downtown Asheville offering acupuncture, massage, infrared sauna, red light therapy, yoga and meditation by appointment.

Hudson Valley, New York

Hotel spa inside The Abbey Inn in Peekskill, overlooking the Hudson River, with six treatments including a Japanese head-and-foot package.

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.

Coorg, Karnataka

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

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.

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.

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.

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.

Scottsdale, Arizona

Hammam-inspired hotel spa at Omni Scottsdale Resort & Spa at Montelucia in Paradise Valley, with private suites and massage, facial and body treatments for

Nashville, Tennessee

A combined salon and day spa in Nashville's Grandview Heights offering massage, organic facials and hair styling, with yoga and a relaxation lounge on site.

Hudson Valley, New York

Day spa near Wallkill and Gardiner in the Hudson Valley offering massage, skincare and energy-healing treatments, with an on-site bed and breakfast for

Vail, Colorado

A Vail day spa offering customized massages and facials plus a recovery room with infrared sauna, cold plunge and yoga mats.

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.