A place of hope in the Czech Republic quietly perseveres in the age of Nazi tyranny, a Moroccan politician sides with the French and an eco-friendly paradise in the Amazon proves to be unsustainable.

An underground labyrinth can warp the mind and turn friend into foe.

In modern-day Turkey, on the coast of the Aegean Sea, archaeologists discovered hilltop ruins that are believed to be the site of one of the world's most enduring stories.

Half-built castles stand as a whimsical reminder of a neighborhood that was supposed to feature thermal baths and panoramic views; the ambitious project came to an abrupt halt when the construction company began to face financial difficulties...

This spooky, unfinished amusement park serves a different purpose nowadays.

In a California desert, a once glittering Hollywood hotspot gets converted into a top-secret interrogation center for POWs.

A mysterious American pyramid built out of Cold War paranoia, a haunted prison, and a cluster of structures in the Atlantic are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

Traces of 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, and new discoveries reveal how they were built and why they were abandoned.

The world's strangest ghost towns are home to dark secrets, creepy buildings and eerie sights; new discoveries reveal why they were abandoned.

Graffiti scratched into the walls of a military base on the British coast sheds light on a secret raid against the Nazis.

A Polish castle becomes entwined in the hunt for lost Nazi treasure, the heir of an American business tycoon gets caught in a web of controversy and an Irish estate is embroiled in a fight for freedom.

An American ghost town in the Amazon jungle, a secret Nazi base, and a deadly concrete fortress 866 miles long are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

A terrifying sea fortress, a highway in the Amazon that suddenly vanishes, a mysterious structure in the shadow of the Statue of Liberty are deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

A Beatles legend builds a state-of-the-art studio on a Caribbean island.

This fortress once stood between the Ancient Roman and Persian Empires.

Notorious gunslinger John Dillinger once pulled off a daring escape from this unassuming jail.

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

A fantasy land lies in the heart of Alabama, a place of refuge in Ireland becomes a house of horrors, a South Korean city is scarred by a violent crackdown and traces of a brutal industry remain along the arid Namibian coast.

A secret Russian military base in the Gobi Desert, a strange complex in an American wasteland, and a relic high atop a mountain are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

In Alaska, the ruins of a massive compound point to eerie evidence of an apocalyptic mystery. New discoveries reveal why this strange marvel was built in the snowy wilds of the Last Frontier and why it was abandoned.

At an infamous prison in the Amazon, dangerous criminals faced hard labor, a hostile environment and death by guillotine; today, it's deserted and new discoveries reveal why this hellish compound was built and abandoned.

An abandoned system of caves was once the meeting place of a secret society that worshiped Satan and performed black magic, and new discoveries at this mysterious site reveal what really happened here and why a Founding Father was a frequent guest.

An abandoned theme park is home to secrets of a forgotten, imaginary world.

Experts reveal 10 of the world's most iconic abandoned places.

A porn baron dreams up a hedonistic paradise to avert nuclear catastrophe.