Spas with thermal pool

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.

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

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.

Ginzan Onsen, Yamagata

A riverside hotel spa in Ginzan Onsen with a thermal bathing pool, overnight stay and day-pass access for non-guests.

Kurokawa Onsen, Kumamoto

Okunoyu is a ryokan onsen in Kurokawa Onsen, Kumamoto, with outdoor thermal baths open to day visitors and overnight guests, daily 8:30am–8:30pm.

Shibu Onsen, Nagano

A ryokan in Shibu Onsen with indoor and outdoor hot-spring baths fed by two blended mineral springs, open only to overnight guests.

Arima Onsen, Hyogo

Hotel spa in Arima Onsen with Arima's rare iron-rich "ginsen" waters, outdoor baths, sauna and jacuzzi, run as an all-inclusive overnight stay.