Spas with day pass

Beppu, Oita

A budget mineral-mud and colloid hot-spring bathhouse in the Myoban district of Beppu, open daily for walk-in day soaks or an overnight stay.

Karlovy Vary, Karlovy Vary Region

A 5-star medical spa and wellness hotel beside Karlovy Vary's colonnades, with seven saunas, five pools and a day pass for non-guests.

Da Nang

A Korean-style bathhouse and onsen complex in Da Nang's Hoa Xuan area, with hot spring baths, 11 sauna rooms, massage and a riverside restaurant.

Gero, Gifu

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

Bad Füssing, Bavaria

Medical spa inside Hotel Mürz in Bad Füssing-Safferstetten, open daily 8am-7pm with walk-in day passes for facials, massage and physiotherapy.

Dogo Onsen, Ehime

A roughly 3,000-year-old public hot spring bathhouse in Matsuyama, designated an Important Cultural Property, open daily with walk-in day passes from 700 yen.

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.

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

Hajdúszoboszló, Hajdú-Bihar

A medical thermal bath in Hajdúszoboszló, Hungary, with iodine-bromine-salt water pools treating rheumatic and joint conditions, open daily 7am–7pm.

Beppu, Oita

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

Saint-Malo, Brittany

A seafront thalassotherapy center in Saint-Malo with an Aquatonic seawater pool circuit, day passes, and multi-day cure packages in a Belle-Époque building.

Pärnu, Pärnu County

A 193-room medical spa hotel in Pärnu with a pool and sauna complex, salt therapy, physiotherapy and water aerobics, open to day visitors.

Nikko, Tochigi

Walk-in public onsen in Nikko with mountain views, a sauna, and a cafeteria, closed Thursdays and open 10am–9pm other days.

Nashville, Tennessee

Day spa and medical spa on the third floor of The Westin Nashville downtown, with nine treatment rooms, a dry cedar sauna, steam showers and walk-in access to

Mexico City, Quintana Roo

A Japanese-style hotel spa in Mexico City's Cuauhtémoc district with tatami suites, outdoor onsen baths and a $2,080 day pass for couples.

Piešťany, Trnava Region

Spa Irma on Piešťany's spa island offers historic mud and mirror thermal pools, a hydrotherapy circuit and a 60-treatment medical spa menu, adults only.

Austin, Texas

A day spa and med spa in North Burnet offering massage, facials, and injectables, with walk-ins and day passes accepted.

Sapporo, Hokkaido

Natural hot spring inside Sapporo's Jasmac Plaza Hotel in Susukino, open to day visitors and hotel guests alike, with sauna and a rest lounge.

Ibusuki, Kagoshima

Oceanfront outdoor onsen in Ibusuki where the two gender-assigned baths swap daily, with views of Mount Kaimon, the East China Sea, and Take-yama.

Atlanta, Georgia

A medical spa in Atlanta's Five Points district offering walk-in treatments, a private lounge, refreshments and luggage storage.

Napa Valley, California

Adults-only hotel spa in downtown Napa with thermal circuits, sauna, steam and cold plunge, plus massages, facials and medical aesthetics.

Ho Chi Minh City

A Korean-style jjim jil bang in Ho Chi Minh City with six heated rooms, a Dead Sea mineral soaking pool, and massage, hair-wash and facial services.

Noboribetsu, Hokkaido

A plain neighborhood bathhouse in Noboribetsu, Hokkaido, offering 100% source-fed hot spring water in two mineral varieties, about 10 minutes from the station.

San Diego, California

A La Jolla medical spa specializing in lymphatic drainage, colon hydrotherapy and detox treatments, open since 1993, adults only, by reservation.