Mine Onsen; Hotaru no Yu
Tsushima, Nagasaki, Japan
- Location
- Tsushima, Nagasaki, Japan
- Water type
- thermal, sodium chloride
- Temperature
- 38 °C
- pH
- 7.3
Water profile
Thermicity
Neutral
LowHigh
Soothing — neither hot nor cold, perfect balance.
Mineralisation
Restorative
LowHigh
Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Mine Onsen, known as Hotaru no Yu, is located in Tsushima, Nagasaki Prefecture. Its sodium-chloride thermal water reaches 38°C. An indoor bath, an outdoor rotenburo bath and a sauna are available.
Insider tip — 'Hotaru no Yu' (firefly spring) at Mine Onsen on Tsushima Island — the strategically vital island sitting midway between Japan and Korea (70 km from the Korean coast). The Battle of Tsushima Strait (1905) — Russia's Baltic Fleet annihilated by Admiral Togo — was fought in these waters. Tsushima is also Japan's last refuge of the Tsushima leopard cat (Prionailurus bengalensis euptilurus), a critically endangered subspecies. The island's hot spring in a firefly valley is a rare peaceful counterpoint to its martial history.
Nearby
Frequently asked questions
How hot is the water?
The water is neutral here, around 38 °C — a perfect balance, neither too hot nor too cold.
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.