Treasure hunters have searched for a lost Incan city of untold wealth for a century, but new technology might finally locate its riches. A strange mountain in Egypt sparks an investigation into Cleopatra's gems and the tomb of Alexander the Great.

A ghost ship is found abandoned on a remote island that's home to one of the world's last uncontacted tribes. A strange labyrinth in Sicily might have a sinister connection to the Mafia. New evidence reveals a mysterious military compound in Russia.

Something strange in the Himalayas could be evidence of a top-secret CIA program to turn monks into killer agents, and cutting-edge science helps experts investigate the truth behind this mysterious anomaly.

Hundreds of shipwrecks in the middle of a desert in Africa. A ghost town where hundreds of its inhabitants have mysteriously died. Something strange in North Korea. Cutting-edge tech helps experts answer these sinister mysteries from space.

A strange circular forest next to a notorious cannibal site. When a crater is spotted in Siberia, experts uncover if it could be evidence of Nikola Tesla's doomsday device. Cutting-edge tech helps experts answer these sinister mysteries from space.

Some of the world's most incredible engineering projects are now deserted. Revisit a Soviet megastructure, a massive Nazi brainwashing complex, and a dangerous desert pass. How were they built? Why were they mysteriously abandoned?

Some of the world's most incredible engineering projects are now deserted. Explore a ghost town that was once a dangerous industrial hellscape, a giant warship at the bottom of the ocean, and a top secret relic from the Cold War.

Some of the world's most incredible engineering is now deserted. Explore what happened to the town located outside of Chernobyl on the eve of disaster, a fleet of ghost ships, and a dangerous mountain road that changed history.

Some of the most incredible engineering projects, now deserted. Explore what happened to a military site that was once a hotbed for nuclear testing, a top secret airbase hidden inside a mountain, and an otherworldly power plant.

Some of the world's most incredible engineering projects are now deserted. See what happened to a classified Soviet machine built to prevent nuclear war, a top secret Nazi facility, and a strange tower that left an enduring legacy.

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

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.