Imokawa Onsen
- Location
- Aizuwakamatsu area, Fukushima, Japan
- Water type
- bicarbonate, carbonated
- Temperature
- 40 °C
- pH
- 6.3
Water profile
Relaxing — deep, immediate muscle release.
Loaded with major ions — the essential minerals (Ca, Mg).
Mineralised water — eases movement and joints.
Imokawa Onsen in Niigata Prefecture forms part of the Yu no Tani Onsenkyo—the Hot Water Valley Spring Cluster—a gathering of thermal springs along a mountain valley whose collective mineral output creates a dense thermal bathing landscape characteristic of Niigata's most prolific geological hot spring zones. The bicarbonate and carbonated waters deliver an effervescent, skin-stimulating mineral soak in which natural CO2 adds lively tactile sensation to the gentle alkaline warmth characteristic of bicarbonate springs, creating a layered mineral experience beyond the simple alkaline soak. The cluster setting of Yu no Tani gives Imokawa Onsen a communal thermal atmosphere where multiple springs serve a concentrated area, reflecting the traditional Japanese understanding of hot spring valleys as complete therapeutic landscapes rather than single-point destinations.