Spas with hot tub

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.

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.

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.

Busan

A large Korean jjimjilbang inside Centum City with 18 hot spring baths and 13 themed heat rooms, open daily 9am–10pm.

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.