Ibusuki, Kagoshima prefecture
Besides its luxurious facilities and beachside setting, Hakusuikan Ryokan offers a bathing area with pools of different temperatures, a large outdoor hot spring, a steam room and a sauna. But the resort is famous for its black sand baths-visitors are buried up to the neck in warm sand heated by natural hot springs-which they say increase blood circulation and refresh the body by discharging waste through perspiration. Your most difficult choice here: choosing to stay in a Western-style room or a Japanese-style tatami room facing the water.
Hakone Kowakien Yunessun Hot Springs Amusement Park and Spa Resort
Hakone, Kanagawa prefecture
Take a break from a hectic business trip in Tokyo with a quick day trip to this popular mountainside destination. Open 365 days a year, Hakone Kowakien Yunessun offers traditional public baths for those looking for the authentic onsen(Japanese for hot spring) experience and a water park to satisfy kids. Feeling adventurous? Leave your swimsuit behind and take a dip in the resort's secluded nude-bathing-friendly springs.
Beppu, Oita prefecture
With over 100 hot spring resorts, Beppu is known as Japan's premier onsen destination. Yumesaki Ryokan is a small, elegant inn with six Japanese-style rooms. Come to relax, to sample the fresh, seasonal cuisine and to bathe in the same-sex indoor hot spring baths or the outdoor co-ed pool.