Katsuura Isobe Onsen
- Location
- Katsuura (Isobe), Chiba Prefecture, 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.
Katsuura Isobe Onsen is situated in Isumi City, Chiba Prefecture, in the Isobe area of the outer Boso Peninsula coast where the Pacific Ocean's powerful influence shapes both the natural landscape and the fishing and surfing culture of this scenic Chiba coastal community. The siliceous thermal waters here complement the rugged Pacific coastline scenery of the Isumi area, whose rivers and wetlands also support traditional rice cultivation and the famous Isumi Rail Line — a beloved single-car railway running through the rice paddy landscapes of the Chiba interior that has become a symbol of rural Japanese charm. These onsen serve both local residents of the Isumi coast and visitors drawn to the Isumi area's combination of Pacific coastal beauty, rural rail culture, and the therapeutic mineral spring traditions of the outer Boso Peninsula.