Ōnuma Quasi-National Park is located on the eastern side of the Oshima Peninsula in Hokkaido, Japan. Covering a total area of 9,083 hectares, it is one of the smallest quasi-national parks in Hokkaido. The park can be accessed by taking the Hakodate Main Line operated by JR Hokkaido and getting off at Ōnuma-Kōen Station.
Located in the southern part of the Oshima Peninsula, the park is about 16 kilometers north of Hakodate City. Within the park are several lakes, including Ōnuma, Konuma, and Junsainuma, which were formed by the volcanic activity of Mount Komagatake, an active volcano. Ōnuma Lake alone is dotted with as many as 126 small and large islands.
During spring, summer, and autumn, visitors can enjoy outdoor activities such as cycling, jogging, boating, and autumn foliage viewing. In winter, the park offers seasonal activities like snowmobiling and smelt fishing.
