Shigira Ōgon Onsen, Miyakojima
Miyakojima is often assumed to have no hot springs, yet inside the Shigira Seven Miles Resort on the island's south coast lies one of Japan's southernmost and westernmost natural onsen. Golden sodium-chloride water rises undiluted from 1,250 m underground into separate men's and women's open-air baths and saunas wrapped in subtropical greenery, plus a swimsuit 'jungle pool' and lookout bath where families and couples can soak together – there are even floats for a full resort mood. Adults (12+) pay ¥2,000 and children 4–11 ¥1,000; guests of Shigira Resort hotels pay ¥1,600/¥800. Swimsuit rental is ¥510 and towels are rented for a fee. Open 11:00–22:00 (last entry 21:30), from 12:00 between mid-November and mid-March, every day, with a restaurant and relaxation salon on site. About 15 minutes by car from Miyako Airport, with resort shuttle buses in the evening. Combine it with Shigira Beach, south-coast sunsets and stargazing.