Tennen Onsen; Aso no Yu
Nagaoka, Niigata, Japan
.jpg?width=960)
- Location
- Nagaoka, Niigata, Japan
- Water type
- sodium chloride
- Temperature
- 41 °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
Tennen Onsen Aso no Yu, also in Nagaoka, Niigata Prefecture, draws sodium-chloride water at 41°C. It offers an indoor bath, an outdoor rotenburo pool and a sauna.
Insider tip — Aso no Yu serves western Nagaoka City, the birthplace of Admiral Yamamoto Isoroku who planned the Pearl Harbor attack and led the Japanese Imperial Navy. Nagaoka is celebrated for the August Nagaoka Fireworks festival — one of Japan three greatest fireworks displays — where enormous shells bloom above the Shinano River as an annual memorial to the catastrophic 1945 air raids that destroyed the city and killed thousands of civilians.
Nearby
Frequently asked questions
How hot is the water?
The water runs quite hot here, around 41 °C — a sedative water that brings immediate muscle release.
What type of water is found here?
This spot features sodium chloride water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année.