- Bathing
- Outdoor
Kusatsu produces more hot spring water than any other Japanese resort, and Sainokawara Park is where it runs openly through the rocks before filling a vast rotenburo at the head of the valley.
Balnevia view
Why visit
For the walk through the steaming park and then a very large outdoor bath in snow, surrounded by pine forest.
Recommendations
Hotels nearby
Explore places to stay near Sainokawara Rotenburo.
The water
Thermal water
- Source
- Yubatake and Sainokawara sources
- Mineralisation
- Strongly acidic sulphur-chloride, pH about 2
- Character
- Among Japan's most acidic waters; famously antibacterial
Facilities
- Thermal pools
- Outdoor pools
History
Kusatsu Onsen has been recorded since the twelfth century and was ranked among Japan's finest waters by Edo-period physicians.
Practical information
Wash thoroughly before entering; tattoos may be restricted. Separate male and female baths. The water is strongly acidic — remove jewellery.
Getting there
Bus from Naganohara-Kusatsuguchi station, then ten minutes on foot from the Yubatake through the park.
Location
Related places
More thermal baths in Japan
Hakone/Japan
Hakone Yumoto Onsen
The oldest onsen district in Hakone, where ryokan baths look onto the Sukumo river valley.
Bathing temperature 41°C
Beppu/Japan
Takegawara Onsen
Beppu's 1879 bathhouse, known for its hot sand baths.
Bathing temperature 43°C
Matsuyama/Japan
Dōgo Onsen Honkan
One of Japan's oldest hot springs, in a wooden bathhouse of 1894.
Bathing temperature 42°C