Daishi-yu is one of three communal bathhouses (sotoyu) in Bessho Onsen, Ueda City, Nagano Prefecture, known as the Bath of Jikaku Daishi (Great Master Ennin). Bessho Onsen boasts a 1,400-year history as the oldest hot spring in Shinshu, and the area is called the Kamakura of Shinshu. The bathhouse is named after Ennin (Jikaku Daishi), the head priest of Enryaku-ji Temple on Mount Hiei, who visited and bathed here in 825 AD. It is the only bathhouse among Bessho Onsen three sotoyu that offers 100% free-flowing natural spring water, using Source No. 3. This source was drilled in 1966 from a depth of 180 meters, producing water at 52 degrees Celsius with a flow of 340 liters per minute. The water quality is a simple sulfur spring (mildly alkaline), beloved as a beauty spring that leaves skin silky smooth. The compact and rustic bathhouse has been cherished by local residents for generations. The waters are effective for neuralgia, muscle pain, joint pain, sensitivity to cold, fatigue recovery, and chronic skin conditions.