Spas with walk-ins welcome

Gero, Gifu

An outdoor-only onsen in Gero with rock-built baths, a cascade bath and three-temperature pools, open daily except Thursdays.

Austin, Texas

Contrast therapy studio in East Austin with a communal garden sauna-and-cold-plunge setup, private suites, and red light sessions, day passes from $25.

Chicago, Illinois

Walk-in reflexology and massage spa in the Chicago Loop with foot soaks, hot stone work and a $59 combo massage.

Austin, Texas

A North Austin head spa near The Domain built around Japanese-style scalp massage, with private, couples and group suites by appointment.

Penang

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

Florence, Tuscany

A 650-square-meter spa inside a 14th-century Florence monastery, with thermal pool, guesthouse rooms, bistro and day-pass access.

Hot Springs, Arkansas

Day spa and Aveda salon in Hot Springs with baths, a salt room, oxygen bar and massage, facial and hair services.

Jūrmala

A pool-and-sauna complex inside Pegasa Pils Hotel in Jūrmala, with a 12.5m pool, three saunas, steam room and a salt room; day passes available, minimum age 16.

Eger, Heves

Outdoor thermal bath complex in Eger with sulfurous and radon medicinal pools, family pools and a slide pool, open daily from 9am to 7pm.

Charleston, South Carolina

A West Ashley day spa in Charleston offering lymphatic massage, infrared sauna, halo therapy and foot soaks by reservation, no day pass.

Jackson Hole, Wyoming

A day spa next to the Trailborn hotel in Jackson Hole with an outdoor pool deck, salt lounge and day passes for walk-in soaks or treatments.

San Miguel de Allende, Guanajuato

Family-friendly hot springs park near San Miguel de Allende with indoor and outdoor thermal pools, a kids' splash area, and day passes for walk-ins.

Pärnu, Pärnu County

Thermal bath complex in Pärnu with pools, saunas and hot tubs, open daily 7:30–21:30, day passes from €15 on weekdays.

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.

Palm Beach, Florida

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

Houston, Texas

Day spa in Houston's Westside with a grotto pool, outdoor pool, steam rooms and sundeck, plus an on-site restaurant; walk-ins welcome.

Nozawa Onsen, Nagano

A public day-bathing hall in Nozawa Onsen village with indoor hot and warm baths plus an outdoor hot spring bath, open to walk-ins year-round.

Philadelphia, Pennsylvania

Day spa in Northeast Philadelphia with a full hydrotherapy circuit of saunas, hammam, cold plunge and pools for a $60 day pass.

Atlanta, Georgia

Korean day spa in Norcross near Atlanta with hot and cold baths, sauna rooms, salt room and a restaurant; day pass runs $30.

Sedona, Arizona

A walk-in day spa in Sedona offering five treatments, including a signature Sedona Soul Seeker session, with private suites and an on-site crystal shop.

Gero, Gifu

Gero's riverside hot-spring source pool in the town center, where visitors can touch the water and take photos, though full bathing has been banned since

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.

Temescal Valley, California

Adults-only hot springs resort in Temescal Valley with 19 outdoor mineral pools, red clay baths, and a cave-like grotto, open daily 9:30am-5pm.

Calistoga, California

A Calistoga hot springs spa built around mud baths, with private couples rooms and mineral pools open daily from 8am to 11pm.