Science Channel HD

A forgotten military fortification connected to a network of secret tunnels are mysteriously hidden within the Rock of Gibraltar; experts investigate and uncover a derelict war-torn complex constructed for a highly classified WWII spy operation.

A series of dark, subterranean vaults lie hidden beneath the bustling streets of Edinburgh, Scotland; experts investigate and uncover a vast network of tunnels and chambers that contain a history of opportunity, crime and destitution.

A once majestic theater hosting entertainment for generations in lavish surroundings now lies mysteriously derelict in Cleveland; experts investigate a record-breaking heavy metal concert event that would spell its eventual downfall.

A research complex housing two enormous satellites is now mysteriously derelict in the rural expanse of Woodbury, Ga.; experts investigate and uncover a facility where planetary scientists explored possible evidence of extraterrestrial intelligence.

On the volcanic island of Kolombagara, explorers uncover a mysterious man-made cave in the dense jungle; a researcher finds two unknown animal skulls in Vietnam; human remains are discovered in a narrow chamber of a South African cave system.

In the jungles of southern Mexico, a rancher discovers dozens of skulls and bones on a cave floor; strange grass-covered domes are investigated in the Philippines; archaeologists uncover carved stone figures on the Hawaiian island of Kauai.

A declassified letter written by President Kennedy demands that the CIA share its UFO data with NASA; a bizarre pattern on the surface of Mars could be a coded alien message; investigators find a rocket crash-landed in a crater on the Moon.

Scientists wonder why Jupiter is hotter than it should be; the Curiosity Rover finds something strange on Mars; detectives turn to NASA for help with a murder cold case.

When astronomers discover a rogue black hole speeding through the Milky Way, they investigate how much danger this cosmic monster poses to Earth, and what would happen if it ever entered our solar system.

If a massive asteroid collides with Earth, it could end life on the planet as one knows it; new discoveries reveal just how close civilization is to apocalypse and what it would take for the world's leading space agencies to stop it.

We don't yet know where the edge of the universe is or what happens there; but thanks to cutting-edge technology and new discoveries, experts might finally reveal the secrets of the phenomena.

The disappearance of the SS Cotopaxi helped launch the legend of the Bermuda Triangle; a team of experts follows fresh leads with cutting-edge tech to investigate if a mysterious wreck off the coast of Florida is indeed the long-lost ship.

When a sister ship of the Titanic gets embroiled in war with a hidden enemy, the former luxury liner is sent to the bottom of the ocean; new discoveries and cutting-edge underwater technology might finally reveal the secret history of its sinking.

New evidence in the Bermuda Triangle could reveal that Nazis got closer to America than ever believed; using the latest cutting-edge underwater technology, experts investigate the truth behind the shipwreck that shouldn't exist.

New discoveries reveal the treasures of a ghost fleet of Japanese ships at the bottom of the South Pacific, and using cutting-edge underwater technology, experts investigate a top-secret superweapon that could have changed the course of World War II.

A cutting edge investigation into a deep-sea graveyard of 25 shipwrecks reveals the dark secrets of the biggest naval battle in history, and using the latest tech, experts follow new evidence into the mysterious abyss of long-lost battleships.

A mysterious shipwreck at the bottom of Lake Erie could be the oldest wreck in America's most notorious ship graveyard, and using cutting-edge underwater archaeological methods, experts investigate new leads in this 200-year-old cold case.

Satellite images capture a strange castle-like structure hidden in the dense and remote woodlands of Scotland; expert archaeologists investigate and uncover an area with a bloody history linked to the birthplace of the world's oldest secret society.

Satellite images capture a bizarre pattern of rocks in the shape of a large fingerprint on a remote Swedish island; experts investigate and uncover a mysterious labyrinth with links to ancient Viking black magic and dark, mystical rituals.

Satellite images capture a bizarre pattern of large concentric circles formed in a remote English forest; experts investigate and uncover a top secret experimental bomb testing site critical to WWII British weapons development.

Aerial drone imaging captures a sophisticated complex of lost, ancient Roman buildings in Yorkshire.

Satellite images capture a gigantic oval among a bizarre grid pattern that's carved into the dense forests of New Jersey; experts investigate and reveal a landscape linked to infamous prohibition activity and a prolific WWI munitions factory.

Satellite images capture a mysterious collection of sprawling towns that appear to be completely unoccupied in Belarus; experts investigate and uncover a horrendous state-sanctioned cover-up responsible for claiming thousands of innocent lives.

Aerial drone imaging captures a sophisticated complex of lost, ancient Roman buildings in Yorkshire.