Nishinasuno Onsen
- Location
- Nasushiobara, Tochigi, Japan
- Water type
- calcium-rich
- Temperature
- 42 °C
- pH
- 7.3
Water profile
Relaxing — deep, immediate muscle release.
Loaded with major ions — the essential minerals (Ca, Mg).
Soft water — natural, classic buoyancy.
Nishinasuno Onsen in Nasu Shiobara City, Tochigi Prefecture, draws from two distinct spring sources—Otaka no Yu (Eagle Hot Water) and Mori no Yu (Forest Hot Water, known as the Marronnier source)—creating a multi-spring thermal experience 3.7 km northwest of Nishinasuno Station in the volcanic highland zone north of the Kanto plain. The sulfated and simple waters combine to provide a mineral profile of complementary character, with sulfate minerals lending the water a smooth feel and the simple alkaline component ensuring a skin-softening, accessible soak for guests of all constitutions. Set within the broader Nasu-Shiobara thermal region, Nishinasuno draws from the same volcanic geological wealth that makes this corner of Tochigi one of Japan's premier onsen resort destinations.