“Battleship Island” is one among 505 uninhabited islands in the Nagasaki Prefecture about 15 kilometers from Nagasaki itself. The island was populated from 1887 to 1974 as a coal mining facility. In 1959, its population density was 835 people per hectare (83,500 people/km2) for the whole island, or 1,391 per hectare (139,100 people/km2) for the residential district, the highest population density ever recorded worldwide.
Further Reading: Hashima Island (Wiki)
Related Posts: Japanese History