Yunotsuru Onsen Hoken Center; Hotaru no Yu
Minamata, Kumamoto, Japan
- Location
- Minamata, Kumamoto, Japan
- Water type
- thermal, sodium chloride
- Temperature
- 39 °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
Yunotsuru Onsen Hoken Center; Hotaru no Yu is located in Minamata, Kumamoto Prefecture. The sodium-chloride thermal water reaches 39°C here. Indoor bath, outdoor bath (rotenburo) and sauna round out this facility.
Insider tip — 'Hotaru no Yu' (firefly waters) at Yunotsuru Onsen Hoken Center in Minamata — one of Japan's most significant cities, forever defined by the Minamata disease tragedy (1950s-70s), when mercury-contaminated wastewater from Chisso Corporation poisoned thousands of residents through contaminated fish. Today Minamata is a global symbol of environmental recovery: the bay has been rehabilitated, the community rebuilt. Fireflies — sensitive indicators of clean water — have returned to Minamata's rivers. The thermal baths here celebrate healing in every sense.
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 & sodium chloride water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année.