Innaiyo Onsen
Usa, Oita, Japan
- Location
- Usa, Oita, Japan
- Water type
- thermal, sodium chloride
- Temperature
- 40 °C
- pH
- 7.3
Water profile
Thermicity
Sedative
LowHigh
Relaxing — deep, immediate muscle release.
Mineralisation
Restorative
LowHigh
Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Innaiyo Onsen is located in Usa, Oita Prefecture. Its thermal, sodium-chloride water emerges at 40°C, pH 7.3. The facility features an indoor bath, an outdoor rotenburo bath and a sauna.
Insider tip — 'Innaiyo Onsen' (院内予温泉) in the Innai area of Usa city, Oita. Innai (院内) in Usa is notable for its extraordinary stone arch bridges — the Innai Stone Bridge Group (院内橋群), a collection of historic Meiji-era stone arch bridges that have been designated an important cultural landscape. The thermal springs here serve farming communities that have cultivated the Usa plain since the Nara period (when Usa Shrine was already the domain's most powerful religious institution).
Nearby
Frequently asked questions
How hot is the water?
The water runs quite hot here, around 40 °C — a sedative water that brings immediate muscle release.
What type of water is found here?
This spot features thermal & sodium chloride water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année.