Kaede-no-Yu is a public day-use hot spring facility directly connected to Yudanaka Station on the Nagano Electric Railway. Opened in 2003, this municipal facility is named after the approximately 400-year-old maple tree standing beside the footbath. The history of Yudanaka Onsen dates back to the 7th century, and the area is famous for its connection to the haiku poet Kobayashi Issa. The spring water is a sodium-chloride and sulfate hot spring with a mildly alkaline pH of around 8.5. The source temperature reaches approximately 93 degrees Celsius with a flow rate of about 100 liters per minute. The facility offers 100% natural hot spring water in a free-flowing style. Indoor baths feature hinoki cypress and granite stone baths, while outdoor baths include teppei-seki stone and rock baths. The bathing areas are swapped between men and women monthly. On the 26th of each month, special seasonal baths are offered featuring apples, lavender, bamboo leaves, and other ingredients. The building is constructed on the station platform, allowing guests to watch trains arriving and departing from the rest area. A free footbath is available at the entrance, and the adjacent Kaede-no-Yakata (former Yudanaka Station building) is a registered tangible cultural property worth visiting.