Ancient Aliens

Experts examine a recently discovered Peruvian city that has upended the historical timeline of South America. Could it also provide evidence that Peru's incredible ancient sites were built with the help of extraterrestrials?

Experts count down the world's top 10 most mysterious sites, from the towering Easter Island statues to the megalithic blocks of Stonehenge. Could these extraordinary places provide evidence of extraterrestrial visitation?

Alien experts count down the world's top 10 alien cover-ups, from the Roswell incident to recently released UFO videos captured by Navy jets. Has there been a massive cover-up regarding the truth about an extraterrestrial presence on Earth?

Mount Shasta in northern California is known as a hotbed of strange events. Could the mountain's unique geology and placement on Earth be attracting beings from other worlds... and even other dimensions?

Scientists now know that seven human-like species lived alongside Homo sapiens for thousands of years. But why is it that only humans survived? Is it possible that we were the product of extraterrestrial experimentation?

Experts count down the world's top 10 alien encounters, from the first reported abduction to an incident in Ancient Rome that changed the course of human history. Could these incredible accounts be actual encounters with visitors from the stars?

Experts count down the top 10 alien artifacts, from an ancient figurine of a modern-day airplane to mysterious crystal skulls whose origins are entirely unknown. These objects could provide evidence that extraterrestrials once walked among us.