A Russian hole to hell in the Arctic, a military base in America's wild west, and a strange looming tower are mysterious deserted engineering projects. Then the mystery of an abandoned alien Nazi structure and a Soviet monolith are revealed.
A mysterious pyramid built out of Cold War paranoia, a haunted prison, and a cluster of structures in the Atlantic are mysterious deserted engineering projects. Then, the mystery of a secret structure on a mountain and an industrial compound are revealed.