About 60 minutes from central Tokyo, this scenic hot spring facility is embraced by the rich nature of Akikawa Valley. Its greatest feature is the natural hot spring with an astonishing alkalinity of pH10.01. The silky, uniquely smooth texture is highly regarded as a beauty bath. The sauna room is a dry type installed in the outdoor area, letting you enjoy authentic heat close to 100°C. For cooling down, a cold plunge bath is available in the open-air area, where you can soak while surrounded by crisp outdoor air. In winter, the temperature can drop to near-single digits, offering a cooling experience that changes with the seasons. Enjoying an outdoor air bath while listening to the babbling of the valley stream and the songs of the birds promises the ultimate nature sauna experience that makes you forget all about everyday life.