An eerie prison with a dark past that became the setting of an iconic Hollywood movie and alien monoliths on a strange and remote island are deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

An alien Nazi structure that changed history, a strange Soviet monolith known as the Tower of Death, and a concrete ocean giant are deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

A deserted town in Spain with a bloody past and a ghost fleet heading nowhere are homes to dark American secrets, and new discoveries reveal how they were built and why they were abandoned.

A haunted lighthouse on Lake Michigan, a town where everyone seems to have vanished all at once, and a secret complex of tunnels beneath London are deserted engineering projects.

A ghost ship thousands of miles away from where anyone expected, a bridge to nowhere in Florida's Hurricane Alley, and a haunting mountain complex with a bloody secret are deserted engineering projects; new discoveries reveal why they were abandoned.

A strange deserted city in America's heartland, an eerie gigantic wall deep in snow-capped mountains, and a mysterious top-secret Soviet facility are deserted engineering projects. New discoveries reveal how they were built & why they were abandoned.

An entrance to the underworld in the American wild, a haunting Soviet underwater prison, and a strange complex of towers in a forest of ice are deserted engineering projects; new discoveries reveal how they were built and why they were abandoned.

An alien Stonehenge with a sinister purpose, an eerie building filled with strange labyrinths, and an endless concrete track in the middle of nowhere are deserted engineering projects, and new discoveries reveal why they were abandoned.

New discoveries reveal how an unfinished Nazi fortress was built.

Eerie ghost ships stranded in an alien desert, sinister ruins known as the Dragon's Teeth, and a ghostly complex with a bloody past are deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.