Shimoda Onsen
- Location
- Shimoda, Shizuoka, Japan
- Water type
- sodium chloride
- Temperature
- 41 °C
- pH
- 7.3
Water profile
Relaxing — deep, immediate muscle release.
Loaded with major ions — the essential minerals (Ca, Mg).
Dense, salty water — you float without effort.
Shimoda Onsen is located in Shimoda, a port city at the southern tip of the Izu Peninsula in Shizuoka Prefecture — a place where the Pacific opens wide and where Japan's modern history intersects in the form of the 1854 Convention of Kanagawa, signed in this very harbour. The Izu Peninsula's geothermal activity is well established, fed by the volcanic arc that runs along Japan's Pacific coast.
The sodium-chloride spring flows at 41 °C with a neutral pH of 7.3, producing the characteristic warmth and saline softness associated with this mineral type — a sensation that clings pleasantly to the skin and sustains heat long after the bath. Shimoda's setting adds a maritime dimension to the experience: the combination of ocean views, subtropical vegetation, and the sodium-rich warmth of the spring creates an atmosphere that is distinctly coastal and openly sensory. Shimoda Onsen is an invitation to slow down in a town that has always understood the value of an unhurried arrival.