An environmentally protected area within a national park, a scenic spot for autumn leaves where the dam and nature interweave

A 102.5m-high arched concrete dam completed in 1972 in Minami Ward, Sapporo, for the purpose of flood control and hydroelectric power generation on the Toyohira River. The dam lake is named Jozanko (Lake Sadayama) and can store water equivalent to about 30 cups of Sapporo Dome. Located in the Shikotsu-Toya National Park, the 2-km distance from the dam entrance to the dam is closed to general vehicles, motorcycles, and bicycles all year round for environmental protection, so visitors must walk or take an electric bus.

The area around the dam is a scenic spot surrounded by steep rock slopes, and together with the dam's dynamic sightseeing discharge (from June 1 to October 31 every year from 9:00 to 16:00), it forms a spectacular sight. It is particularly popular as a place to view the autumn foliage in Sapporo City.