Kusatsu Onsen Gunma Premier
Kusatsu, Gunma, Japan
- Location
- Kusatsu, Gunma, Japan
- Water type
- sulfurous
- Temperature
- 53 °C
- pH
- 6.5
Water profile
Thermicity
Sedative
LowHigh
Relaxing — deep, immediate muscle release.
Mineralisation
Bio-active
LowHigh
Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Experience the premier thermal spring of Japan's Kusatsu Onsen, a UNESCO Global Geopark since 2015. This sulfurous hot spring boasts an extremely acidic pH level of 2, making it one of the most unique in Japan. Relax and rejuvenate in this natural wonder, steeped in history and tradition since the 16th century. Discover the perfect blend of relaxation and Japanese culture.
Insider tip — Kusatsu Onsen is Japan's most celebrated hot spring town, producing 32,000 liters of strongly sulfurous water per minute from the Yubatake field at the village center, which is stirred by hand with long wooden paddles in the traditional yumomi ceremony to cool the scalding spring. The highly acidic water (pH around 2) is credited with powerful bactericidal properties and has attracted pilgrims and travelers for over a thousand years. The Sainokawara open-air bath is the largest free communal pool in Japan at 500 square meters. Visit in winter when snow frames the steaming outdoor baths for an iconic scene.
Nearby
Frequently asked questions
How hot is the water?
The water runs quite hot here, around 53 °C — a sedative water that brings immediate muscle release.
What type of water is found here?
This spot features sulfurous water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année (idéal automne-hiver).