Lost Photos, Sandy Irving, & Unexplained Floating Creatures: 5 Stunning Mt. Everest Mysteries

The Perfect Prison that Became a Nightmare

5 Mysterious Objects Watching Us from Earth's Orbit

The Red Truck Inside Reactor #4: The 5 Mysterious Machines of Chernobyl

5 Mysterious People Castaway at the Ends of the World

Russia is Building a "Monster": 5 Mysterious Military Projects Captured in Recent Satellite Photos

In 1803, a UFO was found off the coast of Japan. What was it, and who was inside?

5 World-Changing Inventions That Were Secretly Erased from History

5 Stunning Nuclear Mysteries

5 Unexplained People Who Appeared Out of Nowhere

5 Most Mysterious Ancient Soviet Artifacts

5 Mysterious Aircraft Lost While Carrying Unexplained Cargo

5 Unsolved Volcano Mysteries

"DO NOT ANSWER": 5 Mysterious Radio Signals and Numbers Stations

Titanic Disaster: 5 Mysteries That Still Haunt the World

Oak Island Treasure Pit and The Real One Piece: 5 Biggest Unsolved Pirate Mysteries

5 Inventors With Mysterious Inventions Who Strangely Disappeared

Bohemian Grove: 5 Mysteries of the Elite Meeting That Still Rules the World

The UFO Patents: 5 Military Inventions of Unexplained Technologies

Dark Cargo: 5 Mysterious Container Ships at Sea

5 Mysterious UFO Crashes Before Roswell

A Skull Found in a Tree, A Deadly Dancer, & Stolen Atomic Bomb Plans: 5 Mysterious Female Spies

A Mysterious President Photo, a Secret FBI Dig, and a Lost Submarine: 5 Unsolved Civil War Mysteries

A Massive Vehicle Under Ice, Unexplained Radio Signals & Pyramids: 5 Unsolved Antarctica Mysteries

The Most Mysterious Person of the Cold War: The Unsolved Case of the Isdal Woman

Mysterious Passengers, An Unexplained Message and Ghost Pilots: 5 Unsolved Aviation Mysteries

An Unexplained Jewel from Space and The Location of Atlantis: 5 Unsolved Ancient Desert Mysteries

5 Unsolved Soviet Mysteries

5 Unsolved Mysteries of the Death Valley Desert

A Lost Room at the Bottom of the Sea, The Ark Vault and Ben Franklin's Secret: 5 Unexplained Rooms