Fuse Onsen
Saku, Nagano, Japan
- Location
- Saku, Nagano, Japan
- Water type
- thermal, bicarbonate
- Temperature
- 39 °C
- pH
- 8
Water profile
Thermicity
Sedative
LowHigh
Relaxing — deep, immediate muscle release.
Mineralisation
Restorative
LowHigh
Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
BicarbonatesSodiumCalcium
Fuse Onsen, an onsen in Saku, Nagano, Japan, offers a soak in thermal bicarbonate water at 39°C, alongside an outdoor bath (rotenburo) and a sauna for a relaxing break.
Insider tip — Fuse Onsen in Saku, eastern Nagano — gateway to the Chichibu-Tama-Kai National Park and surrounded by fields of the famous Saku lettuce. The bicarbonate-rich spring waters reflect the mountain geology of the Joshinetsu highlands. A tranquil rural soak in the Shinshu style.
Nearby
Frequently asked questions
How hot is the water?
The water runs quite hot here, around 39 °C — a sedative water that brings immediate muscle release.
What type of water is found here?
This spot features thermal & bicarbonate water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année.