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.

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

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

A mysterious castle was once a fairytale estate, but today, the building is said to be haunted, and experts investigate the secrets of this eerie fortress and the ghostly stories inside.

A mysterious town in the hills of South Africa was once a booming community, but today, the eerie place is deserted; 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.

Special access to the world's strangest disaster zones reveals the buried secrets, eerie sightings, and long-lost treasures in ruined, apocalyptic hellscapes; new discoveries reveal why they were built and why they were abandoned.

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.

Discover how aluminum foil, snowboards, contact lenses and bread are made.

Discover how compact discs, mozzarella cheese and pantyhose are made.

Discover how toothpicks, acrylic bathtubs, helicopters and beer are made.