A disintegrating tower once a thriving cultural hub now stands hollow and derelict in Monrovia, Liberia; experts investigate and uncover a landmark skyscraper left to decay in the wake of a bloody political coup.

Conspiracies swirl around an abandoned military base in Long Island, where it's alleged that covert government experiments took place underground.

A building in Colorado is still marked with bullet holes from a Wild West shootout between union members and state militia.

In the former Soviet Union, this theater and others like it were used to influence the minds of the masses.

In Panama, a military base stands on the frontlines against a tyrant.

A New Jersey jail is overwhelmed by a wave of anger, a Polish stronghold becomes a tool for WW1 propaganda and an English country retreat provides safe harbor for fugitives.

Experts uncover a derelict resort complex constructed by the Russian mafia.

A mysterious town in South Africa is deserted, even though it was once a booming community; experts reveal the cataclysm that caused the people of this once-prosperous town to suddenly leave and never come back.

A strange bunker near the Kennedy Space Center once served a top-secret military function should doomsday ever come to the Sunshine State; experts use declassified intel to reveal the sinister purpose of this forbidding facility and why it was abandoned.

An abandoned castle is the site of hundreds of horrific murders perpetrated by the mysterious countess who once lived there, a woman alleged to be one of the most prolific killers in history; new discoveries reveal what really happened here.

Experts examine a military cover-up with extraterrestrial objectives.

Abandoned towers in southern Greece are the ruins of a fearsome warrior civilization descended from the Spartans, and new discoveries reveal the role these towers played during generations of violent blood feuds among the clans that lived here.

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.

The ruins of an abandoned prison are evidence of a chaotic riot that put the prisoners in charge; special access to its burnt-out interior reveal how inmates took over Ireland's Alcatraz and why it is deserted today.

Experts investigate the ruins of a spy’s former battlefield.

A desert island contains a marooned structure with a contagious past.

New discoveries reveal how an unfinished Nazi fortress was built.

On a strange island off the coast of Croatia, the mysterious ruins of a long-abandoned hideout look like they once belonged to a James Bond super-villain, and new discoveries reveal why it was built and why they were abandoned.

On a desolate island near Greece, abandoned buildings are evidence of a group of people that were forbidden to leave; experts reveal who was forced to stay here and if there was a cover-up to conceal what really happened at this strange place.

A massive, alien-like fortress built into a mountainside is the central node to a network of pipelines that race outwards like tentacles; behind-the-scenes access reveals the secrets of why this strange complex was built and why it was abandoned.

Experts investigate the deadly legacy of an abandoned sea fort.

The remnants of a desolate ghost town are uncovered in Azerbaijan.

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.

A vast network of subterranean bunkers in the American west was home to the power to destroy nations, but today, this facility is deserted, and new discoveries reveal why this eerie place was built and why it was abandoned.