Kazawa Onsen
- Location
- Kazawa, Nagano Prefecture, Japan
- Water type
- bicarbonate, sulfurous, carbonated
- Temperature
- 40 °C
- pH
- 6.5
Water profile
Relaxing — deep, immediate muscle release.
Rich in active gases or metals — a strong mineral character.
Mineralised water — eases movement and joints.
Kazawa Onsen — Birch Stream Spring — in Gunma Prefecture offers a remarkable triple mineral profile of bicarbonate, sulfurous, and naturally carbonated waters — a geologically complex spring of exceptional richness that combines the gentle alkaline warmth of bicarbonate minerals, the volcanic character of hydrogen sulfide, and the lively tactile stimulation of natural CO2 effervescence in a single layered mineral bath of extraordinary compositional complexity. The birch stream name evokes the graceful highland streams lined with white birch (sirakaba) that characterize Gunma's most beautiful volcanic highland landscapes, connecting the spring's complex mineral character to the delicate, refined natural aesthetic of birch forest and clear mountain stream. This spring's triple mineral combination and birch stream setting make Kazawa one of Gunma's most mineralogically sophisticated and aesthetically evocative thermal spring discoveries.