Spas with day pass

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.

Krynica-Zdrój, Lesser Poland

Mountain resort spa in Krynica-Zdrój with indoor and outdoor pools, a sauna complex, and a clothing-optional 18+ zone; day passes available.

Portorož, Coastal-Karst

Hotel spa on Portorož's seafront promenade with heated seawater and thermomineral pools, open to day visitors as well as hotel guests.

Velingrad, Pazardzhik

Hotel spa in Velingrad with mineral-water pools, saunas, steam rooms and a hammam spread over 4,000 square metres; day passes are available.

Archena, Murcia

A 19th-century thermal hotel in Archena with direct access to a Roman-era spring complex, open to day visitors as well as overnight guests.

Houston, Texas

Upscale day spa at The Houstonian in Houston with 22 treatment rooms, soaking pools and a sundeck; pool access comes with a 50-minute-plus treatment, not a

Reykjavik, Capital Region

Eight oceanfront geothermal pools in Hvalfjörður, 45 minutes from Reykjavík, plus steam baths, a bistro and guest houses for rent.

Beppu, Oita

A hot-spring bathhouse in Beppu's Kannawa district, running since 1922 on 100% unblended spring water with walk-in day passes.

Zurich

Thermal baths and rooftop infinity pool set in a former Zurich brewery's historic vaults, with a Roman-Irish spa ritual and day-pass access.

Miami, Florida

A co-ed Turkish hammam and day spa in North Miami offering a $125 day pass with saunas, steam rooms, a hydromassage pool and an on-site Turkish restaurant.

Ischia, Campania

Family-run thermal pool park on Ischia's Maronti beach, open since 1973, with three sulfur-water pools, a sauna and direct beach access.

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.

Duluth, Georgia

A 24-hour Korean bathhouse in Duluth with a $30 day pass, sauna rooms, cold plunge, thermal circuits and a junior Olympic pool.

New York City, New York

A 24-hour Korean jjimjilbang-style day spa in Midtown Manhattan with saunas, a soaking tub, and a $135 body-scrub signature treatment.

Wiesbaden, Hesse

A 16+ textile-free thermal bath in central Wiesbaden with Roman-style architecture, saunas, steam rooms and a cold plunge pool.

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.

San Diego, California

A walk-in day spa in San Diego's Hillcrest neighborhood with massage, cryotherapy, salt therapy and a $100 all-day wellness pass.

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.

Chantilly, Virginia

King SPA is a Korean bathhouse in Chantilly, VA, with gender-separated clothing-optional baths, mixed saunas, a restaurant, and day passes for walk-ins.

New York City, New York

A Korean jjimjilbang-style spa in Palisades Park, NJ, with ten heated sauna rooms, hot tubs, cold plunge and a $69 day pass, open daily 9am to 2am.

Chicago, Illinois

A 24-hour Korean bathhouse and sauna complex in Niles near Chicago, with 11 heat rooms, hot and cold pools, and a $45 day pass covering walk-in access.

Bad Kissingen, Bavaria

Thermal bath and sauna park in Bad Kissingen with 10 indoor/outdoor pools, nine saunas and a day pass around €40.

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

Day spa in Burr Ridge, about 20 miles outside Chicago, built around a hydrotherapy circuit with whirlpool, cold plunge and steam room.