Kokuritsu Koen; Shiroyama Onsen
Sakaide, Kagawa, Japan
Illustration photo — not a verified picture of this exact spot.
- Location
- Sakaide, Kagawa, Japan
- Water type
- sodium chloride, thermal
- 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
Shiroyama Onsen, near a national park in Sakaide, Kagawa Prefecture on Shikoku island, heats sodium-chloride thermal water to 40°C, with an indoor bath, an outdoor rotenburo and a sauna.
Insider tip — An onsen within or near the Seto-Naikai National Park in Sakaide, Kagawa — the Seto Inland Sea National Park, Japan's first and most visited national park. Shiroyama (castle mountain) overlooks the straits where the iconic Seto Ohashi bridge links Honshu and Shikoku.
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 sodium chloride & thermal water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année.