Kusatsu Onsen

Kusatsu Onsen, a mas de 1.100 metros en las tierras altas de Gunma, ha sido celebrado en la literatura y la poesia japonesa durante mas de 1.300 anos. Su elemento mas caracteristico es el Yubatake — una cuadricula de madera en la plaza del pueblo por donde el agua mineral fluye a 95°C antes de ser enfriada para el bano. El agua es una de las mas acidas de los grandes onsen japoneses, con un pH de aproximadamente 2,1.

Kusatsu Onsen sits at over 1,100 metres in the Gunma highlands and has been celebrated in Japanese literature and poetry for more than 1,300 years. Its defining feature is the Yubatake — a wooden grid of channels in the town square where steaming mineral water flows at 95°C before being cooled for bathing. The water is among the most acidic of any major Japanese onsen, with a pH around 2.1, produced by volcanic hydrothermal activity beneath Mount Shirane. Kusatsu's traditional bathing method, jikan-yu, involves immersing in very hot water for precisely three minutes — a practice maintained in several communal bathhouses. The town's high elevation means snow-covered streets in winter, making the contrast of outdoor hot baths against snowfall one of Japan's classic seasonal experiences.

Kusatsu Onsenは日本・Gunmaに位置する硫黄泉・酸性泉。源泉温度は95℃、標高1156mの地に湧出する。泉水は強酸性（pH約2.1）の泉質、硫酸塩泉・塩化物泉を豊富に含む、総溶解固形物1580 mg/Lが特徴だ。720年頃から利用されてきた。スキンケア・リラクゼーション・血行など多様な温浴療法が行われる。施設では入浴・蒸し風呂・全身浴などが体験できる。