Watch Ancient Aliens

There are great minds that can predict the future, seers who possess extrasensory abilities and visionaries that almost push humanity forward into a new age; these great thinkers have credited their genius to outside inspiration.

Strange activity, UFOs, bizarre orbs of light and electromagnetic anomalies are regularly witnessed around the world; many of these sites correspond to locations where ancient civilizations chose to build and rebuild their most sacred architecture.

Whether inscriptions, enigmatic crop formations and encoded sacred architecture signify communication with extraterrestrial visitors.

Archaeologists uncover a prehistoric grave containing our revolutionary cousin, see more in this clip from Season 1, "Aliens and Human Evolution."

Thousands of UFO sightings are reported in the United States every year, and intriguingly many of them center around U.S. military operations. Recently, the United States government has officially acknowledged that it is investigating unidentified aerial phenomena.

Humans are just scratching the surface when it comes to what we know about ancestors from the distant past. Lost cities, ancient texts, mysterious carvings, and unexplained structures provide clues to a long-forgotten time that goes further back in history than we could have ever imagined. From Egypt to China and even Antarctica, Ancient Astronaut theorists propose that the deeper people dig, the closer they will come to proving an extraterrestrial influence on Earth's ancient inhabitants.

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Summary is not available.

Summary is not available.

In the 20th century, a mysterious British woman who claimed to be the reincarnation of an ancient Egyptian priestess shocked Egyptologists by accurately locating countless structures and artifacts in the Nile Valley. Could it be that she was carrying out an otherworldly agenda–and preparing for the return of the Egyptian gods?

In the nearly 2,000-year-old text called "The Zohar," there is a curious passage that describes hidden realms beneath the surface of the Earth, each of which is said to be populated by both human and non-human intelligences.

Ancient cultures around the world often referred to the gods as the "Immortals" - but could they have encountered extraterrestrial beings that had achieved eternal life? And if these visitors genetically engineered the human race, as Ancient Astronaut Theorists suggest, is it our destiny to become immortals as well?

In Ireland, the notion of the fairy folk dates back thousands of years and originates with stories of powerful shining beings who came down from the sky; exploring if these tales have been inspired by ancient alien visitation.

Ancient Aliens has followed investigators across the globe as they've gone directly to the sites where signs of alien life have been found. Now, Giorgio Tsoukalos takes a look back at the most incredible evidence ever uncovered that could offer definitive proof that we are not alone in the universe.

Giorgio Tsoukalos takes a look back at the most mysterious artifacts from all over the globe, artifacts that he believes provide undeniable proof of extraterrestrial contact.

Ancient Aliens has examined the oldest and most mysterious rock art on Earth--up close and in person. Now, Giorgio Tsoukalos takes a look back at the incredible hieroglyphs, petroglyphs, and geoglyphs that he believes tell a worldwide story--of alien visitation.

Ancient Aliens has followed investigators across the globe as they've gone directly to the sites where unexplained incidents have been reported. Now, Giorgio Tsoukalos takes a look back at the most extraordinary encounters that, as far as he's concerned, provide evidence of an extraterrestrial presence on Earth.

Some 2,600 years ago, the most-sacred relic of the ancient world suddenly disappeared from history: The Ark of the Covenant. Could descriptions of the Ark's incredible power reveal that it was a highly advanced technological device?