Spas with reservation required

Portland, Oregon

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

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.

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.

Scottsdale, Arizona

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

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.

Oslo

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

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.

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.

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.

Indianapolis, Indiana

Day spa in Allisonville, Indianapolis with sauna, steam room, thermal pool and cold plunge, plus about 10 massage and facial treatments for solo visits or

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.

Miami, Florida

An upscale day spa on Miracle Mile in Coral Gables with sauna, steam room and cold plunge, known for a $200 signature treatment and couples packages.

Scottsdale, Arizona

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

Port Douglas, Queensland

Day spa in Port Douglas with sauna, steam room, thermal pools and cold plunge, offering massages, facials and body treatments by appointment.

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.