Yunomine Onsen, Hot spring resort in Tanabe, Japan

Yunomine Onsen is a hot spring resort in a narrow valley along the Nakahechi trail of the Kumano Kodo in Tanabe, Wakayama Prefecture. A hot creek runs through the centre, lined with wooden walkways and a stone embankment, and steam rises from the water. The spring water is high in sulfur, sodium and hydrogen carbonate and emerges at about 90 °C.

The spring was discovered roughly 1,800 years ago and served pilgrims traveling the ancient Kumano Kodo pilgrimage route for centuries. It became an important stopping place for religious travelers seeking rest and healing during their sacred journeys.

The name comes from Toko-ji temple's honzon, a Yakushi Nyorai image formed by mineral deposits around the spring, whose chest once spouted hot water: "yu no mune" (hot water's chest) became "Yunomine". The temple still stands in the centre, and on 8 January the Yunomine Yoka Yakushi festival offers hot spring water for prosperity and protection from misfortune.

The best time to visit is outside holiday periods, when the village is less crowded and the baths are more relaxing. Comfortable shoes are important, since most inns and bathhouses are within walking distance of each other.

The Tsuboyu bath is a small wooden cabin over a stone-lined pool that holds one or two people. It is the only hot spring inscribed in the UNESCO World Heritage site of the Kumano Kodo pilgrimage route. The water is said to change color seven times a day, and the bath is used privately in timed sessions.