Hashima Island a ghost town ? it was once the most densely populated island in the world; now it's completely empty. People became interested in the island after finding an underwater coal deposit directly under it. As time went on, tightly packed apartment complexes were constructed for the miners and laborers, providing its density record. But folks left as quickly as they came when the coal ran out. It's now a rock and concrete ghost town in the middle of the ocean. View the most beautiful lakes in America.