A water source and forest that protects diverse flora and fauna. A sanctuary for nature observation with few man-made structures.

Located on a hillside southwest of the Hitsujigaoka Observation Hill, about 30 minutes by car south of central Sapporo, the park consists of a reservoir called Nishioka Suigen-ike, the Tsukisamu River, wetlands and forest in the upper reaches of the river. Suigen-ike was constructed in the Meiji period (1868-1912) as a water supply facility for the former army by damming the Tsukisamu River, and was later taken over by Sapporo City and developed into a park. The park is minimally maintained, except for the entrance area, and is blessed with water and greenery, and is home to a wide variety of flora and fauna. The park is rich in nature, ideal for bird watching and nature observation.