壹岐島
Tsushima is the closest Japanese territory to the Korean Peninsula, lying approximately 50 km from Busan. On a clear day, the hills and mountains of the Korean peninsula are visible from the higher elevations on the two northern mountains. The nearest Japanese port, Iki, situated on Iki Island within the Tsushima Basin, is also 50 km away. Tsushima Island and Iki Island are collectively within the borders of the Iki–Tsushima Quasi-National Park, designated as a nature preserve and protected from further development. Much of Tsushima (89%) is covered by natural vegetation and mountains. Tsushima Island has many mountains such as the Mt. Ohira, Mt. Yatate, Mt. Hokogatake, Mt. Koyasan, Mt. Ontake, Mt. Gogen.