Found around 15km from Nagasaki, Hashima was used as a coal mining facility between 1887 and 1974, with its population reaching a peak of 5,259 people in 1959, or 216,264 per square mile. After petroleum replaced coal throughout Japan in the 1960s, Hashima was abandoned, and is now known as "Ghost Island". A small portion of the island was reopened to tourists in 2009, and sightseeing boat trips often stop here.