Hashima Island: Japan's Forbidden Battleship

Once home to over 5,000 people crammed into concrete high-rises on a facility smaller than a city block, Hashima Island was the most densely populated place on Earth. Then, in 1974, the coal ran out and every resident left within months, leaving behind a perfectly preserved snapshot of 1970s Japanese industrial life that has been slowly crumbling into the sea for fifty years.