Once the most densely populated place in the world, this island is now a ghost town.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

This Canadian island is a veritable garden of decay with countless abandoned structures dotting the landscape.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

The elaborate clockwork contraptions in this Scottish gallery create small worlds of whimsy and horror.

While this monument tile is shrouded in mystery it also marks the end of the longest ever human chain.

The largest coin pyramid in the world is a carefully balanced stack of over 1,000,000 pieces.

Underwater roads undetectable from the surface used for escape routes from foreign invaders.

This lonely Lithuanian chapel looks more beautiful and haunting in decline than it ever did in life.

This Latvian shot factory is still used twice a year to manufacture bullets the old-fashioned way.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

A bizarre house filled with an astounding array of collections.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

A toxic ghost town sitting atop a massive coal fire.

Train tunnel running underneath Quebec City.

Industrial ruin decimated this tiny New England company town in a fashion no one saw coming… and even fewer remember today.

Rock face that shares a name with Mary Shelley's famous doctor.