Hashima Island, nicknamed Gunkanjima or Battleship Island as it resembles a massive battleship, near of Nagasaki. It is now an abandoned cluster of buildings rising in the Pacific ocean. From 1887 until 1974, the small island served as a coal mine for the Mitsubishi Mining Company and held up to 5259 residents, resulting in the highest population density ever recorded worldwide. In 1974, the mine was closed, and its residents had to leave Gunkanjima. Japan submitted an application to UNESCO to register the island of Hashima and 22 other sites for UNESCO World Heritage status. South Korea has criticised the bid because the application included sites where Koreans were forced to work during Japanese colonial rule. Japan occupied South Korea from 1910 until its defeat at the end of World War II in 1945. According to the South Korean government during this time about 150,000 Koreans were forced to labour in Japan.