Mysterious legends and crumbling ruins are all that is left of our planet's lost worlds. But could there be proof of ancient alien visitors hidden among the artifacts of civilizations that have long vanished? Strange carvings suggest the Mayan city of Copan was ruled by the descendants of otherworldly beings. And some believe the ancient Nazca people altered their bodies--and their lands--to signal the star gods to return. Are the astounding accomplishments of lost civilizations merely the products of ancient folklore--or could they have been something... out of this world?

For thousands of years, there have been places around the world considered dangerous to humans. Might these locations hold the key to an otherworldly connection? At Australia's Black Mountains, local myths speak of ancient serpent gods and hikers disappearing. Every year hundreds are drawn to a dark forest at the base of Mount Fuji in Japan--to commit suicide. What causes these places to be evil? Could there be evidence that past extraterrestrial activity lead to the negative energy in Earth's evil places?