The world's abandoned structures hold new evidence about the lives and deeds of history's greatest heroes and villains, and using the latest discoveries at these mysterious sites, experts count down the ten most significant.

A collection of ramshackle structures with a mystical facade lie mysteriously deserted on the tropical island of Bali; experts investigate and uncover the ruins of a bizarre amusement park complex with a disastrous past.

Experts investigate bunkers that conceal a deadly nuclear secret.

Experts investigate the deadly legacy of an abandoned sea fort.

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

A war-torn Italian ghost town immortalized by a legendary Hollywood director blurs the lines between fiction and reality; experts investigate and uncover a forgotten landscape of ruins captured in a WWII documentary.

The ruins of a dreamlike Polish palace hide an astonishingly dark history that's shrouded in mystery to this day; experts investigate and uncover an ornate gothic structure that concealed a nightmare of Nazi experimentation.

A breathtaking stainless steel tower seems otherworldly and out of place in the remote mountain forests of Croatia; experts investigate and uncover a dark past of Nazi-led conflict and a monument to a desperate fight for survival.

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

The haunting remains of an isolated ghost town high in the Colorado mountains suggest a once booming mining community left in devastation; experts uncover an inhospitable land of shattered dreams where fortune seekers chased the American dream.

An enormous concrete box with bizarre circular openings looms on the coast of an island near mainland China; Experts investigate and uncover tunnels leading to an enormous underground complex that nearly triggered a nuclear war.

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

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

Experts reveal how Mafiosi was imprisoned on a Mediterranean island.

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

Experts investigate a classified military wasteland with a deadly past.

Experts investigate the ghostly remnants of a beautifully constructed town.

Experts uncover the haunting remnants of a settlement in the Nevada desert.

Deserted buildings are evidence of a city’s lost industrial past.

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

Experts examine a military cover-up with extraterrestrial objectives.

The ruins of a historic Scottish castle is now a bewitching wilderness of hidden dangers with deadly booby traps obscured afoot; experts and historians reveal a bygone Second World War military hospital with bizarre ties to an infamous Nazi occupant.

In a remote Louisiana swamp, the ruins of a massive industrial operation suggest that something evil once happened here, and new discoveries at this eerie site reveal what these abandoned buildings were for and why they were deserted.

An abandoned industrial complex by Lake Michigan was once a top-secret military compound that protected America from enemy attacks; new discoveries reveal what really happened here and why the government turned its back on this juggernaut.

An island of dense jungle is home to an abandoned complex with a dark past of bloodshed and rebellion, and new discoveries at this deserted place reveal why it was built and the gruesome circumstances of its downfall.

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.

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.

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.

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.

An eerie set of buildings in Paris is evidence of an unspeakable evil; new discoveries reveal the horrific things that happened here, and why they were abandoned.

A strange bunker in a treacherous landscape once belonged a notorious dictator who's paranoid fantasies drove bizarre and elaborate feats of engineering; new discoveries reveal the secrets of these structures and why the nightmares that built them.

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 town in the Nevada desert is the ruins of an American Atlantis, destroyed by catastrophic floods when the Hoover Dam was built; experts investigate the secrets of this eerie ghost town as water levels recede and the city reemerges.

A one-time fairytale castle is rumored to be haunted; experts investigate the secrets and ghostly stories of this eerie fortress.

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.

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 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.

A haunted prison with a terrifying past once housed America's most notorious criminals, but today, the fortress stands in ruin, and experts reveal evidence of ghostly secrets hidden in the crumbling jailhouse walls.

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.

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

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.

The ruins of a once-palatial compound contain the secrets of one of history's most notorious criminals, and new discoveries reveal why this high-security estate was built and why it was abandoned.

Tunnels filled with human bones lie beneath the streets of Paris, and this horrifying engineering marvel points to a dark secret; new discoveries reveal why this grisly underground death maze was built and why it was abandoned.

A ghost town in the American West was once a Gold Rush hotspot and one of the most violent places in America. Today, there are legends of a secret treasure buried in the surrounding hills, and new discoveries might finally reveal its true location.

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.

A strange complex of tunnels on the grounds of a bizarre mansion were under lock-and-key for a century. Since its rediscovery, some believe its mysterious place is a gate to hell. New discoveries reveal its secret purpose and why it was abandoned.

Near the destroyed city of Pompeii, an eerie complex of underground tunnels snake beneath a volcano, and some believe these passages were intended as a gateway to hell. New discoveries reveal exactly why they were built and why they were abandoned.

A strange complex of buildings on a remote tropical island was once home to a large seaside community, but today, locals avoid the area and claim that it's haunted. New discoveries reveal why this eerie place was built and why it was abandoned.

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.

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.

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.

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.

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.

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.

New discoveries reveal how an unfinished Nazi fortress was built.

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 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 strange Cuban prison, an eerie escape route built for Armageddon, and an underwater marvel that changed history are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

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.

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.

A secret structure on a sinister mountain, an industrial compound swallowed by a forest, and a mysterious run in a sand dune are strange deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

A strange alien shrine on a mountain peak, a bridge built in the Alaskan wilderness, and an American castle with a dangerous secret are mysterious deserted engineering projects. New discoveries reveal how they were built and why they were abandoned.

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.

America is the home to strange engineering projects that now lie in ruins, and new discoveries reveal how they were built and why they were suddenly abandoned.

The series about abandoned engineering achievements begins with a Soviet megastructure, massive Nazi brainwashing complex and dangerous desert pass.

Exploring a ghost town that was once a dangerous industrial hellscape, a giant warship at the bottom of the ocean, and a top-secret relic that could have changed the Cold War.

Exploring what happened to the large town just outside of Chernobyl on the eve of disaster, a fleet of ghost ships, and a dangerous mountain road that changed history.

Stories of incredible engineering projects that are now deserted, including a massive military site that was once a hotbed for nuclear testing, a top-secret airbase hidden inside a mountain, and an otherworldly power plant.

Abandoned engineering projects include a classified Soviet machine built to prevent all-out nuclear war, a top-secret Nazi facility, and a strange tower that left an enduring legacy.

Some of the world's most incredible engineering projects are now deserted; Explore what happened to a cutting-edge research complex built by a visionary genius, an ambitious Nazi project that met a sinister end, and a Cold War relic that changed history.

Some of the world's most incredible engineering projects now lie in ruins. These deserted places are home to extraordinary mysteries and untold secrets, and we revisit them to understand how they were built, and why they were abandoned.

Go inside the abandoned city of Chernobyl to follow an investigation into the truth behind the nuclear meltdown there over 30 years ago. New evidence reveals that this accident may be one of the greatest sabotages in history.

Uncover the secrets of Nazi engineering projects that now lie in ruins. These deserted places are home to extraordinary mysteries and untold secrets, and are revisited to understand how they were built, and why they were abandoned. This episode is a compilation of segments from S01E01, "Nazi Ghost Town", S01E05, "Soviet Doomsday Device", and S01E04, "Wild West Apocalypse".

Uncovering the secrets of Soviet engineering projects that now lie in ruins; these deserted places are home to extraordinary mysteries and untold secrets, and we revisit them to understand how they were built, and why they were abandoned. This episode is a compilation of segments from S01E03, "Phantoms Of Chernobyl", S01E01, "Nazi Ghost Town", and S01E05, "Soviet Doomsday Device".

Uncovering the secrets of American engineering projects that now lie in ruins; deserted places play home to extraordinary mysteries and untold secrets; revisiting them to understand how they were built and why they were abandoned. This episode is a compilation of segments from S01E01, "Nazi Ghost Town", S01E06, "The Tesla Conspiracy", and S01E03, "Phantoms Of Chernobyl".

Uncovering the secrets of military engineering projects that now lie in ruins; these deserted places play home to extraordinary mysteries and untold secrets; revisiting them to understand how they were built and why they were abandoned. This episode is a compilation of segments from S01E02, "Curse Of Hell Island", S01E03, "Phantoms Of Chernobyl", S01E04, "Wild West Apocalypse".