Anan Onsen
TypeNatural Hot Spring
A simple hot spring with very high alkalinity at pH 10.3. The water is characterized by a silky, enveloping feel on the skin when you soak.
Nagano Prefecture's largest public bath and a strongly alkaline, skin-beautifying hot spring
Nagano Anan Town
Anan Onsen Kajika-no-Yu in Anan Town, Nagano Prefecture, is a mountain leisure complex featuring one of the largest public bathing areas in the prefecture. Its simple hot spring has a very high alkalinity with a pH of 10.3 and a silky, soft texture that is popular as a beauty-enhancing bath. The facility offers a very hot high-temperature sauna and an approximately 27°C source spring bath that can be used in place of a cold water bath, allowing guests to enjoy a unique cool-down routine together with cold water showers.
TypeNatural Hot Spring
A simple hot spring with very high alkalinity at pH 10.3. The water is characterized by a silky, enveloping feel on the skin when you soak.
Sauna TypeDry Sauna
Stove Typeelectric
Capacity8people
A compact, thermally efficient dry sauna at about 90–92°C. It is set up to allow for thorough sweating.
Water Qualityhot_spring
Capacity5people
An approximately 27°C source spring bath used in place of a cold water bath. A popular routine is to cool the body with a cold water shower and then relax slowly in the mildly warm spring water.
Closed Days: Wednesday
4923 Tomikusa, Anan Town, Shimoina District, Nagano Prefecture 399-1505, Japan
Gender Access
Gender Separated

Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more
Nagano Prefecture's largest public bath and a strongly alkaline, skin-beautifying hot spring
Nagano Anan Town
Anan Onsen Kajika-no-Yu in Anan Town, Nagano Prefecture, is a mountain leisure complex featuring one of the largest public bathing areas in the prefecture. Its simple hot spring has a very high alkalinity with a pH of 10.3 and a silky, soft texture that is popular as a beauty-enhancing bath. The facility offers a very hot high-temperature sauna and an approximately 27°C source spring bath that can be used in place of a cold water bath, allowing guests to enjoy a unique cool-down routine together with cold water showers.
TypeNatural Hot Spring
A simple hot spring with very high alkalinity at pH 10.3. The water is characterized by a silky, enveloping feel on the skin when you soak.
Sauna TypeDry Sauna
Stove Typeelectric
Capacity8people
A compact, thermally efficient dry sauna at about 90–92°C. It is set up to allow for thorough sweating.
Water Qualityhot_spring
Capacity5people
An approximately 27°C source spring bath used in place of a cold water bath. A popular routine is to cool the body with a cold water shower and then relax slowly in the mildly warm spring water.
Closed Days: Wednesday
4923 Tomikusa, Anan Town, Shimoina District, Nagano Prefecture 399-1505, Japan
Gender Access
Gender Separated

Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more