The History Channel

If extraterrestrials influenced human history, can evidence of their existence be found in hidden tunnels and caverns around the world? Could a cave in Ecuador contain metallic books inscribed with secrets of alien technology? Was an ancient underground city in Turkey built with alien help... or as a refuge from an alien attack? Rumors of the U.S. military working alongside aliens in a secret base inside a mesa in New Mexico continue to swirl, Native American legends mention strange inner-Earth beings, and recent archaeological discoveries in the Yucatan may point to an extraterrestrial reality behind.

At nearly 14,000 years old, the ruins of Puma Punku are the oldest and most baffling on the face of the Earth. No one knows who designed and built this complex of sophisticated inter-locking blocks, and then vanished. Researchers investigate the ruins on-location in Peru and present new computer analyses. Forensic evidence on the ground, together with local myths and legends, suggest this site may have been designed and even once inhabited by a species of extraterrestrials.

Scientists are continually challenged by unidentified strains of bacteria with mysterious origins. Could some of our most crippling plagues and epidemics be traced to the darkest voids of space--or even extraterrestrial intervention? During the Black Death of the Middle Ages, people reported bronze flying ships emitting a strange mist. As recently as 2011, NASA scientist Richard Hoover published evidence of life in meteorites. Is it possible that ancient aliens--as small as microbes--have shaped human history?

If ancient aliens visited Earth, were they responsible for catastrophes, wars and other deadly disasters to control the fate of the human race? The story of the Great Flood sent by deities to destroy civilizations exists in many prehistoric cultures. There are ancient descriptions of extraterrestrial battles that caused wide-scale destruction, and even reports of UFOs lurking in the shadows of recent natural disasters. The Book of Revelations and the Dead Sea Scrolls describe a future apocalyptic battle between good and evil that will destroy our world. Are these ancient texts proof that aliens are hostile and planning a violent return? Or might they be our saviors, ensuring our survival as a species during times of devastation?

One of the most frightening horror stories ever written was Dr. Jekyll and Mr. Hyde. Was this story, however, Robert Louis Stevenson's disturbing fantasy or was it based on a series of blood-curdling episodes that took place in the town of Edinburgh? Follow a team of historical detectives who use evidence from recent excavations and historical documents to look under the grand fa ade of Edinburgh. Watch as an underworld of streets and houses with a blood-soaked history of grave robbers, body-snatchers and unspeakable crimes is uncovered. Computer graphics allows the viewer to fly over, enter the streets, walk through the halls and peer into the Edinburgh of long ago.

The Hittites are the forgotten superpower of the Bible. Hattusha, the capital was the heart of their empire. They were a highly advanced military powerhouse who struck fear into the hearts of all their enemies, yet the Hittites disappeared as quickly as they emerged--the greatest vanishing act in history. Follow a team of historical detectives as they use evidence from recent excavations, scientific studies and historical documents to piece together clues to determine what the ancient Hittite empire looked like. Computer graphics allow viewers to fly over, enter the streets, walk through the halls and peer into this lost world.

Whatever is in store--a massive cosmic collision, a global environmental disaster, an Armageddon-like religious showdown, or a more subtle transformation--many believe that December 21, 2012 will mark a major shift in the history of our planet. There is no cogent distinction between the sobering facts and hysterical fiction--what, if any, modern scientific proof exists? Is there any other compelling evidence throughout history that 2012 will be a year of unprecedented, deadly upheaval? This special looks for the parallels between the nightmarish daily headlines and the 2012 prophecies from Nostradamus and others. From the mystical realms of the Guatemalan jungles to the Hopi elders and Mayan shaman to respected thinkers of the modern age--Nostradamus' doomsday warning will be cast in a frighteningly modern context.

For years, the team has been tracking an elusive prey only seen at night--ships, shaped like triangles, impossibly huge, and videotaped over cities around the world. But are they ours, or theirs? The team investigates numerous UFO sightings that have recently been reported in Sonora, California, a charming old West town nestled in the Sierra Nevada Mountain Range nicknamed Triangle Alley. What makes these sightings so compelling are rare daytime footage of triangles in flight. This footage will be digitally analyzed to determine if these are indeed UFOs and not military jets. The team will also visit Texas to speak to military experts and witnesses to compelling triangle sightings. It's speculated that these triangle craft have been visiting us for centuries.

Could gold be the ultimate link between humans and aliens? A church in southern France is said to hold the key to alchemy--and a gateway to another part of the universe. Locals in Cusco, Peru believe UFO sightings are connected to lost gold at the bottom of Lake Puray. And some believe underneath the Great Sphinx of Giza lies an entire library left behind by extraterrestrials--a library stored on gold.

What if I told you that the crystal ball for our future may be found in the work of Leonardo Da Vinci? Experts believe an obscure sketch that was stolen and hidden by a Cardinal in the Catholic Church may be part of Da Vinci's cryptic prophecies. But what exactly was Leonardo predicting, and why was it so dangerous that a Cardinal felt the need to hide it from the world? To comprehend Da Vinci's predictions for our future, the team investigates history's greatest mind, uncovering Da Vinci's controversial political views, his blasphemous obsession with death, and even the mystery shrouding the Mona Lisa's identity.

Best-selling author Brad Meltzer and his team try to penetrate Bohemian Grove, one of America's most tightly guarded gatherings of the rich and powerful. The Decoded team converges on the group's hideaway in a northern California redwood forest to pursue rumors of ritual sacrifice and secret agreements that control the lives of everyday Americans. Brad soon finds out just how difficult it is to uncover Bohemian Grove's secrets. He knew sending the team into the Grove would be risky, but he never expected they'd be calling him for bail money.

The biblical Garden of Eden was taken away from man because of his sins. The Bible says Eden was located east of Israel where four rivers meet--The Tigris and Euphrates and the Pison and Gihon. The later two have long been considered mythical; however recent satellite photography suggests these rivers did exist in Iraq. Another theory places Eden's location beneath the Black Sea. Do texts other than the Bible reinforce the idea of Eden? Both the Babylonian Epic of Gilgamesh and Ancient Greek texts speak of a paradise lost. Sift through the evidence to decode an age-old mystery about how paradise was lost, and where it might be found.

Informational programming.

Informational programming.

Informational programming.

Informational programming.

On November 24, 1963, a stunned America struggled to accept the assassination of President John F. Kennedy two days earlier. As tens of millions stared at their televisions that Sunday morning, they witnessed TV's first live murder--the killing of assassination suspect Lee Harvey Oswald by Dallas strip-club owner Jack Ruby. What was seen for 47 hours as an isolated tragedy became one of the most notable suspected conspiracies in US history. And while the Warren Commission claimed that Oswald and Ruby both acted alone, the House Select Committee on Assassinations concluded in 1979 that JFK's murder most likely resulted from a conspiracy. Now, a new development has shaken both sides of the conspiracy controversy. Recently revealed evidence suggests the CIA may have been tracking Oswald and indicates a possible link among anti-Castro Cubans, Carlos Marcello, Ruby, Oswald, and the CIA.

One of the most frightening horror stories ever written was Dr. Jekyll and Mr. Hyde. Was this story, however, Robert Louis Stevenson's disturbing fantasy or was it based on a series of blood-curdling episodes that took place in the town of Edinburgh? Follow a team of historical detectives who use evidence from recent excavations and historical documents to look under the grand fa ade of Edinburgh. Watch as an underworld of streets and houses with a blood-soaked history of grave robbers, body-snatchers and unspeakable crimes is uncovered. Computer graphics allows the viewer to fly over, enter the streets, walk through the halls and peer into the Edinburgh of long ago.

The Hittites are the forgotten superpower of the Bible. Hattusha, the capital was the heart of their empire. They were a highly advanced military powerhouse who struck fear into the hearts of all their enemies, yet the Hittites disappeared as quickly as they emerged--the greatest vanishing act in history. Follow a team of historical detectives as they use evidence from recent excavations, scientific studies and historical documents to piece together clues to determine what the ancient Hittite empire looked like. Computer graphics allow viewers to fly over, enter the streets, walk through the halls and peer into this lost world.

Whatever is in store--a massive cosmic collision, a global environmental disaster, an Armageddon-like religious showdown, or a more subtle transformation--many believe that December 21, 2012 will mark a major shift in the history of our planet. There is no cogent distinction between the sobering facts and hysterical fiction--what, if any, modern scientific proof exists? Is there any other compelling evidence throughout history that 2012 will be a year of unprecedented, deadly upheaval? This special looks for the parallels between the nightmarish daily headlines and the 2012 prophecies from Nostradamus and others. From the mystical realms of the Guatemalan jungles to the Hopi elders and Mayan shaman to respected thinkers of the modern age--Nostradamus' doomsday warning will be cast in a frighteningly modern context.

For years, the team has been tracking an elusive prey only seen at night--ships, shaped like triangles, impossibly huge, and videotaped over cities around the world. But are they ours, or theirs? The team investigates numerous UFO sightings that have recently been reported in Sonora, California, a charming old West town nestled in the Sierra Nevada Mountain Range nicknamed Triangle Alley. What makes these sightings so compelling are rare daytime footage of triangles in flight. This footage will be digitally analyzed to determine if these are indeed UFOs and not military jets. The team will also visit Texas to speak to military experts and witnesses to compelling triangle sightings. It's speculated that these triangle craft have been visiting us for centuries.