Hashima Island, Nagasaki Prefecture, Japan

It is known for its coal mines and their operation during the industrialization of Japan. Mitsubishi bought the island in 1890 and began the project, the aim of which was retrieving coal from undersea mines. They built Japan's first large concrete building (9 stories high), a block of apartments in 1916 to accommodate their burgeoning ranks of workers (many of whom were forcibly recruited labourers from other parts of Asia) and to protect against typhoon destruction. According to a South Korean commission, the island housed 500 Koreans who were forced to work between 1939 and 1945, during World War II.
In 1959, the 15-acre island's population reached its peak of 5,259, with a population density of 835 people per hectare (83,500 people/km2, 216,264 people per square mile) for the whole island, or 1,391 per hectare (139,100 people/km2) for the residential district.
As petroleum replaced coal in Japan in the 1960s, coal mines began shutting down all over the country, and Hashima's mines were no exception. Mitsubishi officially announced the closing of the mine in 1974, and today it is empty and bare, which is why it is called Ghost Island. Travel to Hashima was re-opened on April 22, 2009 after 35 years of closure.