Taki-no-Yu is one of the three public bathhouses in Kakuma Onsen, located in Yamanouchi Town, Nagano Prefecture. Kakuma Onsen is a historic therapeutic hot spring village said to have been discovered by Rennyo Shonin, a high priest of Jodo Shinshu Buddhism, during the Muromachi period. The area has been beloved by many literary figures including Fumiko Hayashi, Eiji Yoshikawa, and Taikan Yokoyama. The most distinctive feature of Taki-no-Yu is the hot spring water cascading like a waterfall from about 2 meters high on a stone wall built with rocks. The sound of the falling water resonates loudly throughout the bathhouse, which is the origin of its name (Taki means waterfall). The bathhouse has a rustic, quaint atmosphere. The spring water is a sodium-chloride and sulfate hot spring (hypotonic, mildly alkaline, high-temperature spring). The water is quite hot, offering fresh, free-flowing spring water directly from the source. To enter, visitors insert a special wooden key (marked Kakuma-gumi) borrowed from their accommodation, which automatically unlocks the door - a surprisingly high-tech mechanism despite its retro appearance. Since the closure of Kurotori Store, which managed the keys, at the end of 2019, access is now limited to guests staying at Kakuma Onsen ryokans.