Spas with reservation required

Portland, Oregon

Sullivan's Gulch studio focused on sensory-deprivation float tanks, paired with massage and SomaWave sound therapy sessions.

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.

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.

Pagosa Springs, Colorado

Wellness studio in Pagosa Springs offering yoga, Pilates, sound baths and bodywork, with walk-in classes and private appointment sessions.

Pagosa Springs, Colorado

A wellness lounge and day spa in Pagosa Springs offering yoga, pilates, sound baths and bodywork, with day passes and walk-in classes.

Miami, Florida

A Peruvian-themed day spa inside the Victor Hotel on Ocean Drive, South Beach, with a hamam, steam room, sauna and a couples suite.

San Sebastián, Basque Country

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

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.

Bishop, California

A century-old natural hot springs pool near Bishop in the Eastern Sierra, with a cooling waterfall, a separate hot soak, and simple day-use facilities.

Portland, Oregon

A membership-driven wellness club in downtown Portland with hot pools, sauna, steam room and cold plunge, plus massage, skincare and fitness classes.

Chicago, Illinois

Hotel spa on the lower level of the Fairmont Chicago, open to guests for massages, facials and a couples suite with an infinity-edge soaking tub.

Atlanta, Georgia

Membership-based medical spa in Buckhead combining aesthetics, massage and facials, and lounge spaces for meditation and recovery.

Phuket

Adults-only Ayurvedic resort on a Rawai hillside with doctor-led Panchakarma programs, a saltwater pool and 47 private villas.

Austin, Texas

Hotel spa at Omni Barton Creek with steam room, sauna, cold plunge and a rooftop pool overlooking Hill Country, open daily 9am-7pm.

Napa Valley, California

A family-run day spa in Vacaville near Napa Valley, offering massage, facials, waxing and a private whirlpool tub by appointment only since 1997.

Scottsdale, Arizona

North Scottsdale day spa with massage, facials, sauna, steam and a thermal pool, plus private suites for couples and groups.

San Francisco, California

Hotel spa at The Huntington Hotel on Nob Hill with a heated soaking pool, sauna, steam room and terrace, open daily 8am-7pm; treatment booking required.

San Francisco, California

Neighborhood day spa in Noe Valley with a private outdoor hot tub, offering massage and a combined soak-and-massage package for two.

Denver, Colorado

A Whittier day spa in Denver where private suites pair beer and wine baths with infrared saunas and a self-pour taproom.

Denver, Colorado

A Littleton day spa centered on private suites with beer and wine baths, infrared sauna, zero-gravity massage and a self-pour taproom.

Santa Fe, New Mexico

A 77-acre hot springs resort outside Santa Fe with spring-fed thermal pools, day-pass soaking packages from $175, and overnight lodging.

Hudson, New York

Adults-only communal thermal baths and steam room in downtown Hudson, NY, with day passes, memberships and treatment-plus-soak packages.

Rishikesh, Uttarakhand

A compact Ayurvedic spa and yoga retreat near Laxman Jhula in Rishikesh, offering six treatments including Shirodhara by appointment only.