#16: Hashima Island, Japan
Often referred to as Battleship Island due to its unique concrete silhouette, this tiny ocean outpost off Nagasaki was once the most densely populated place on Earth. When the underwater coal mines officially closed in 1974, the entire population of five thousand workers evacuated over a single weekend, leaving a massive grid of brutalist apartment blocks to rot in the salty air. The hollow metropolis famously served as the villain’s lair in the James Bond thriller Skyfall.

