Watch Ancient Aliens

The ancient site of Gobekli Tepe challenges everything modern archaeologists believe about mankind's past. The megalithic stone complex was built over 12,000 years ago, which dates it to 6,500 years before Stonehenge, and 5,000 years before the first known civilization was said to have emerged in Mesopotamia. Mainstream archaeologists believe that humans were roaming the Earth as simple hunter-gatherers at this time, but if so, how could they have built such incredible structures? Might they have had help from a more advanced--perhaps extraterrestrial--civilization? According to Ancient Astronaut Theorists, the site serves as the smoking gun for a lost civilization--one whose survivors may have built the site to preserve important information about otherworldly visitors. Does the site offers clues about our extraterrestrial past that the ancients felt compelled to preserve for future generations?

Hundreds of strange disks are discovered in a cave in China that appear to tell the story of an ancient extraterrestrial crash on Earth. Shortly after the disclosure of these artifacts, the disks are confiscated by the Chinese government and dismissed as a hoax. But are they? Ancient traditions from around the world speak of mysterious disk-shaped artifacts that held tremendous power. The Babylonians claimed to have a disk that stood in for their most powerful deity. The Incan leader Pachacuti attributed his rise to a divine disk that fell from the sky. And treasure hunters have been searching for centuries for the acclaimed "Golden Sun Disk" that was hidden from the Conquistadors when they sacked Peru. Ancient Astronaut theorists propose that these disks were more than just sacred objects, and represent some sort of extraterrestrial technology.

In Honshu, Japan, stands one of the country's oldest and holiest Shinto shrines, the Ishi-no-Hoden. Carved from a single rock, it appears to hover over a pool of water and depicts a sky ship of stone that the ancient people witnessed descending from the heavens. This is just one of numerous megalithic structures found throughout Japan commemorating a time when the gods, or perhaps, extraterrestrial beings, descended to Earth.

Across the globe, over 1.5 billion people believe in reincarnation, the belief that a soul can be reborn into a different body after death.

India's Sanskrit texts are filled with incredible stories about advanced technology in the ancient world.

Researchers ask if Cloud computing represents the rediscovery of an ancient repository of knowledge known as the Akashic Record; neuroscientist Dr. Dario Nardi measures the brainwaves of Dr. Deepak Chopra as he enters a state of deep meditation.

A roll of film surfaces containing pictures of a memo informing president-elect Dwight Eisenhower about the existence of a top-secret group of scientists, government officials and military personnel who investigate reports of UFOs.

The ancient Aztec site of Teotihuacan in central Mexico is explored as the possible remnants of a highly advanced, perhaps extraterrestrial, civilization.

Theorists speculate about metal artifacts that could provide physical evidence of extraterrestrials visiting Earth in the distant past; in Jacksonville, Fla. a strange metallic sphere falls from the sky; an ancient aluminum wedge baffles historians.

Starting in 1947, a series of unexplained events and sightings prompts U.S. government officials to become alien hunters; theorists offer evidence that similar endeavors were made thousands of years ago.