Spas with reservation required

Penang

Day spa in George Town offering Thai massage, foot reflexology and full body treatments in private rooms, open daily 11am to midnight.

Durango, Colorado

A hot springs resort in the Animas Valley near Durango, Colorado, with 32 mineral pools, cold plunges, a lap pool and private cedar soaking tubs.

Palm Springs, California

Moroccan-themed inn in Desert Hot Springs with natural mineral hot springs, a spring-fed pool and day-pass access from 9am to 4pm.

Denver, Colorado

Downtown Denver massage studio with 22 treatments, cold plunge and sauna, built for membership-based regular visits rather than one-off day passes.

Portland, Oregon

A reservation-only float spa in Northwest Portland offering private suites for flotation therapy, sauna and cold plunge, with no walk-ins or day passes.

Palm Springs, California

Hotel spa inside the Avalon in Palm Springs, open Thursday through Monday, with a $75 day pass covering jacuzzi, sauna, cold plunge and steam rooms.

Nashville, Tennessee

A Brentwood day spa focused entirely on scalp and head treatments, with private suites and a signature ritual built around halo water therapy.

Kraków, Lesser Poland

A private spa near Kraków that's booked out entirely for one couple or group at a time, with jacuzzi, two saunas and a salt inhalation tower.

Scottsdale, Arizona

Day spa in South Scottsdale focused on facials and a signature holistic massage, with sauna, steam room, thermal pool and cold plunge on site.

Palm Beach, Florida

A West Palm Beach day spa offering facials, massage, waxing and couples packages in private suites, open daily 10am-8pm.

Fishers, Indiana

A recovery-focused studio in Fishers offering whole body cryotherapy, cold plunge, infrared sauna and compression therapy on a day-pass or single-visit basis.

Denver, Colorado

A medical spa in Thornton offering Japanese head spa treatments, body wraps, chemical peels and B12 shots, with sauna, steam room and pool access.

New York City, New York

A below-street-level day spa in NoHo with thermal baths, a three-story indoor waterfall, sauna, steam room and cold plunge, plus massage and facial treatments.

Seattle, Washington

A Bellevue day spa in Wilburton specializing in head spa scalp treatments, massage, facials and couples sessions, with free on-site parking.

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 reservation-only day spa in Revere, near Boston, with sauna, couples suite and tropical rain vichy shower treatments.

Bormio, Lombardy

Adults-only hotel spa near Bormio with thermal pools, a relaxation lounge and a 13-treatment menu; day passes start around €44 for evening entry.

Williamstown, Massachusetts

Day spa in a converted 1762 grist mill on the Green River in Williamstown, offering massage, facials and a private outdoor hot tub.

Scottsdale, Arizona

A moderately priced day spa in South Scottsdale with lake-view suites, massage and facials, plus a dedicated couples treatment room.

Oslo

Waterfront sauna spot on Aker Brygge with shared and private saunas, sea bathing, and sauna boat trips on the fjord.

San Sebastián, Basque Country

A reservation-only massage studio in San Sebastián with a private couples suite and jacuzzi, no day-pass access.

Portland, Oregon

A compact Pearl District day spa centered on Hawaiian lomi lomi-style massage, with private suites and four treatments on the menu.

Bursa

A historic thermal bathhouse and small hotel in Bursa's Kükürtlü district, with separate men's and women's hamams, day passes, and overnight stays.

Boston, Massachusetts

A Finnish kelo-log banya in Newton with sauna, steam room and cold plunge, alternating men's and women's days, day passes from $69.