Written by Aarohi Narain
At the center of Kusatsu Onsen, the Yubatake is the town’s most famous landmark: a cascade of mineral-rich thermal water flowing through a series of wooden channels. It naturally cools the scalding spring water before it is distributed to the town’s many bathhouses, inns, and public onsens.
Kusatsu’s volcanic hot spring water originates from Mount Shirane, an active stratovolcano located nearby. The water emerges from the ground at an intense temperature exceeding 50°C (122°F), with one of the highest natural flow rates in Japan at around 4,000 liters per minute. Unlike many other onsen towns where water needs to be reheated, Kusatsu’s springs produce an endless supply of naturally heated, highly acidic water. These thermal waters are renowned for their antibacterial and skin-softening properties.
The Yubatake is designed to cool the water naturally while maintaining its beneficial minerals. As the water travels through a network of wooden flumes, it releases billowing steam, filling the air with the distinct scent of eggs. The wooden chutes also help to encourage the crystallization of onsen minerals, which can be seen accumulating along the sides. Known as yu no hana, it is later harvested and turned into bath salts or skincare products sold in town.
Located just beside the Yubatake there is a free footbath where visitors can soak their feet in the warm waters. The area around the Yubatake is lined with restaurants and souvenir shops.
