Hashima Island, Japan

It’s no surprise why this island of concrete and steel is nicknamed “Ghost Island”: No one lives here anymore. Also called “Battleship Island” for its shape, the site stands as a monument to Japan’s rapid industrialisation. With more than 5000 people crowded into high-rise apartment buildings in the mid-20th century, Hashima was one of the most densely populated places on earth. Most of those who lived here were coal miners and their families, although the island’s place in history is controversial because it was also the site of forced labour. In 1974, the mine was closed, and everyone up and left. Tours of Hashima to see the crumbling buildings are available; you can also catch the island in the 2012 James Bond film Skyfall.
Cahawba, Alabama, USA

It’s hard to believe, but this site of decomposing cabins was once the capital of Alabama. Now, it’s one of the creepy but real ghost towns around the world. The history of Old Cahawba (also spelled Cahaba) goes in fits and starts: Chosen as the state capital in 1820, the town was abandoned after flooding and the capital moved in 1826, but it reemerged as a distribution point for cotton shipping. During the Civil War, though, its railroad tracks were ripped up and the town was host to a prison for Union soldiers; after the war, another flood drove the remaining residents out. However, the town again found new life as a community for former slave families – at least until around 1900. Since then, the town has been in ruins but is now enjoying yet another rebirth as an archaeological park.
Castle Frankenstein, Germany

Abandoned castle ruins can be seen all over Europe, but the history of 13th century Castle Frankenstein is creepily curious because of its connection to the hidden origins of one of Halloween’s spookiest creatures. A real-life scientist named Johann Konrad Dippel conducted strange experiments here in the early 18th century – including, reportedly, on corpses. Could Dippel have inspired the fictional scientist who shares the castle’s name, and his monster? Although Frankenstein author Mary Shelley never mentioned the castle in her journals, she did pass by on a trip down the Rhine in 1814. Did she hear stories about Dippel from locals? Or perhaps her stepmother, a translator for the Brothers Grimm, read the tale and passed it on? In any case, after being abandoned in the 18th century and rumoured to be the home of a dragon, the ruins of the castle are now open to tourists.