Spas with day pass

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.

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.

Reykjavik, Capital Region

A tiny free geothermal footbath on the Seltjarnarnes coast near Reykjavik, good for warming your feet while watching the sunset or northern lights.

Monroe, Utah

Natural hot spring pools fed by mineral water in rural Monroe, Utah, open 24/7 with day-pass soaking and funky bus and cabin lodging on site.

Nikko, Tochigi

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

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.

Pagosa Springs, Colorado

Victorian-style bathhouse in downtown Pagosa Springs with mineral soaking tubs, a rooftop tub, sauna, cold plunge and on-site massage.

Saturnia, Tuscany

Walk-in thermal park in the Maremma countryside with four outdoor sulfur pools, hydromassage jets and a vascular circuit fed by a 3,000-year-old spring.

Mornington Peninsula, Victoria

Geothermal hot springs and day spa in Fingal on the Mornington Peninsula, with a family-friendly Bath House and an adults-only Spa Dreaming Centre.

Shibu Onsen, Nagano

Reservation-only private hot spring and sauna suites at a Nagano brewery complex, built around a craft beer bathing plan for two to four guests.

Hot Springs, Arkansas

Thermal-water bathhouse on Central Ave in Hot Springs offering soaking pools, private mineral baths and eight spa treatments, minimum age 14.

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.

Kusatsu, Gunma

A large open-air hot spring bath in Nishinokawara Park, Kusatsu, set among forest with mountain and seasonal views, open daily for walk-ins.

Flúðir, Hrunamannahreppur

Iceland's oldest natural swimming pool, built in 1891 near Flúðir, fed entirely by onsite hot springs and a small geyser.

Sierraville, California

A non-profit hot springs retreat near Lake Tahoe with natural spring pools, reservation-only day and evening soaks, camping and rooms, closed Mondays and

Archena, Murcia

Thermal spa resort in Archena, Murcia, with a 3,000m² thermal circuit, outdoor baths and a day pass from €23.

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.

Puyehue, Los Lagos

A hot-springs resort inside Puyehue National Park with two mineral pools, cabins, river-side domes, camping, and day passes for non-guests.

Tuscany

A five-star resort in the Tuscan countryside built around a natural thermal spring, with day passes from €39 for outdoor thermal pools, hydromassage circuits

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.

Idaho City, Idaho

A reservation-only hot springs soak in Idaho City with private tubs, a steam room and a $30 day pass, open five days a week.

Pagosa Springs, Colorado

Hot springs resort in Pagosa Springs, Colorado, built around the geothermal Mother Spring, open daily for day-pass soaking or overnight stays.