Hashima Island, Japan
Hashima Island, commonly called Gunkanjima (meaning "battleship island" for its ship-like silhouette) is an abandoned island lying not far from the city of Nagasaki, Japan. The island was known for its undersea coal mines, and more than 5,000 people resided here in the 1960s. At one time it was the most densely populated place in the world. In 1974, however, the coal mines were closed down, and people gradually left Gunkanjima.