Many people from all over Japan come and visit Tamagawa Onsen for its unique healing properties. The hot spring water here has a pH of 1, making it the most acidic onsen in Japan. People who have sensitive skin or lesions may have a reaction from the acidity, but the ryokan (Japanese inn) thankfully offers different onsen pools that are watered down with a balanced mixture of more alkaline water in addition to the acidic onsen water. These baths are also gender-separated and also include indoor baths.
Visitors who walk around the area can see people lying on the rocks near the sulfur vents for the health benefits it provides. In the valley, the 98-degree hot spring water bubbles above the surface, a sign of the area’s volcanic activity. Hiking is another popular option when visiting the onsen during the fall time since the entire area turns bright red from the autumn leaves. Hiking trails are available from Mount Yakeyama to Goshogake Onsen. Note that Tamagawa’s special waters are only available during mid-April to October, so be sure to check it out between spring and autumn.
Sign up to receive insider tips about the food scene in Japan's most extraordinary areas.