Ōshima (大島; lit. Big Island) is an uninhabited island in the Sea of Japan, 50 kilometers (31 mi) west of Matsumae town and therefore the westernmost point of Hokkaido. It is part of the town of Matsumae in Oshima Subprefecture in Hokkaido, Japan. To distinguish Ōshima from other islands with the same name, it is sometimes known as Oshima Ōshima...