Spas with reservation required

Daylesford, Victoria

A rammed-earth house on 80 hectares near Daylesford, rented whole for up to 10 adults, with in-room massage and a two-night minimum stay.

Miami, Florida

A luxury day-pass wellness circuit inside Carillon Miami Wellness Resort, with sauna, steam, cold plunge and thermal pools in North Beach.

Kuala Lumpur

An onsen-style day spa in Kampung Baru, Kuala Lumpur, with thermal pools, sauna, steam room and couples treatments.

Marrakech, Marrakesh-Safi

A 1,200-square-metre hotel spa at Selman Marrakech built around the Chenot method, with hammams, pools and multi-day wellness programmes.

Atlanta, Georgia

A reservation-only wellness center in Edgewood, Atlanta offering colon hydrotherapy, hyperbaric oxygen therapy, sauna and an oxygen bar for couples or solo

Gold Coast, Queensland

An overnight wellness retreat in Tallebudgera Valley with a cedar sauna, magnesium spa bath, ice bath and a 60-minute aromatherapy massage.

Boston, Massachusetts

A Seaport social wellness club in Boston offering saunas, ice baths, IV therapy, red light and HBOT sessions, with reservations required and no membership

Mexico City, Quintana Roo

A Japanese-style hotel spa in Mexico City's Cuauhtémoc district with tatami suites, outdoor onsen baths and a $2,080 day pass for couples.

Seattle, Washington

An adults-only wellness studio near Green Lake with private infrared sauna suites, therapeutic massage and red light therapy by reservation.

Sedona, Arizona

Customizable wellness retreat center in Sedona offering day packages, private retreats and bodywork sessions by appointment, open daily 9am-7pm.

Taos, New Mexico

A reservation-only wellness studio in Taos offering hyperbaric oxygen, colon hydrotherapy and infrared sauna sessions aimed at altitude recovery.

Merano, Trentino-South Tyrol

An adults-only, guests-only longevity retreat and hotel spa in Merano with a medical-led wellness institute and private suite treatments.

Carefree, Arizona

A 20-plus-acre desert wellness resort in Carefree, Arizona, with a full spa, pools, and 100-plus weekly fitness and mindfulness classes open to day visitors by

Koh Samui, Surat Thani

Kamalaya Koh Samui is an adults-only destination spa and wellness retreat on Laem-Set Rd with over 100 treatments, thermal circuits and multi-day health

Ojai, California

Small wellness retreat at the Lavender Inn in Ojai offering massage, facials, and a beekeeping experience, with couples treatments available.

Oaxaca

A traditional four-door temazcal steam ceremony about 15-20 minutes outside Oaxaca city, paired with an ice-water plunge and overnight rooms.

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.

Catskills, New York

A small storefront in Catskill, NY offering whole-body cryotherapy, infrared sauna and red light therapy sessions, open most days except Tuesday and Wednesday.

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.

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

Solvang, California

A resort spa inside Alisal Ranch, a 10,500-acre luxury guest ranch in Santa Ynez Valley open only to overnight guests by reservation.

Valle de Bravo, State of Mexico

An adults-only luxury wellness retreat on the shore of Lake Avándaro in Valle de Bravo, built into a rock formation and run by reservation only.

Lake Tahoe, California

A wellness studio in Tahoe City offering reiki, massage, meditation, sound healing and yoga classes, open daily from 9am to 7pm.

Kapaau, Hawaii

An oceanfront eco-boutique hotel and wellness retreat on Hawaii Island's North Kohala coast, open to overnight guests only, not day visitors.