Arima Onsen 「有馬温泉」 (Hyogo)
Arima Onsen is one of the oldest hot spring towns in Japan. It has a recorded history going back to the 631 published Nihon Shoki, the second oldest book of classical Japanese history. Arima Onsen lies in a natural mountain setting, yet is close enough to Kobe and Osaka to make a day-trip feasible. The town has two types of hot spring waters kinsen (“gold water”), colored brown with iron deposits and said to be good for skin ailments and muscle pain and the clear ginsen (“silver water”) containing radium and salts and said to cure various muscle and joint pain.
Visitors to Arima Onsen can enjoy hot spring bathing at two public bath houses. Alternatively, several of the town’s ryokan open their baths to non-staying guests during the day.Access : From Kobe, Sannomiya station: take the subway to Tanigami station. Then, take the Shintetsu Arima-Sanda line to Arima-guchi. Transfer to the Arima line and get off at Arima Onsen station (approx. 40mins, 930yen) Bus : Some direct buses are available from Kobe and Osaka.
Kusatsu Onsen 「草津温泉」 (Gunma)
Kusatsu Onsen has the largest natural flow of hot spring water in Japan. Kusatsu Onsen comprises of therapeutic baths that have been popular since ancient times. In Japanese mythology, it is believed to have been founded by Prince Yamatotakeru-no-mikoto.
Gero-onsen 「下呂温泉」 (Gifu)
Gero-onsen is surrounded by the Hida mountain range. It is a simple alkaline spring featuring clear, colorless water with a mild fragrance and softness. There is a large rotenburo (open-air bath) that you can bathe in for free at the south end of the Gero bridge. However, it has no facilities and is exposed to the bridge above.