This movie was made during the zenith of public interest in the ancient astronaut theory, and made the rounds on TV during the mid-80s. It covers many aspects of the phenomenon worldwide, though concentrated mostly in South America, with segments on the Nazca Lines, the ancient city of Tiahuanaco, and, especially, the curious people of the Paracas Peninsula, in southern Peru. It is also where I first heard of the mysterious and controversial Ica Stones, with their astonishing depictions of dinosaurs and humans together, men riding giant birds (stylized aircraft?), global maps, and complex medical procedures. Lest anyone think that the coverage is coming from only one angle, it also includes a segment demonstrating how fake stones could also have been fashioned. A small-time production, to be sure, and, by now, very much obscure, but dealing with the topics at hand quite ably, and I will always remember it fondly.
FYI: The other user review posted here, referring to "Are We Alone in the Universe", based on the works of Zechariah Sitchin, is actually another documentary with the same name, made in 1992. I have seen this one as well, find it just as fascinating as the 1978 movie, and commend both to the reader's attention.