Von Daniken claims that aliens landed in the Nazca Desert back
when humans were still evolving from primitive beings. When the alien
vehicles touched down, they gouged tracks into the desert plain.
According to his theory, the ancient Nazcan natives would have believed that these lines were made by the "fiery chariots of the sky gods." They carefully preserved the tracks the "gods' chariots" had made and even extended them in all directions.