I got into a bit of a debate with a guy at work about the Ancient Aliens thing. He didn't like my certainty that the ancient astronaut theory is total bunk, and I take his point. I can't prove that aliens don't exist. I'm sure they probably do, somewhere.
But I don't need aliens to explain the mysteries of human history. The human mind will do. It didn't take alien technology to build the Incan fortresses, with their tight perfectly fitted stones. All it took was will and ingenuity and hard work.
Prehistoric people were no dummies.
Erich von Däniken doesn't care about why the Nazca people built their lines. Their culture, language, religion, lifestyle, all of this is irrelevant. He only wants to fit their lines into his flying saucer theory.
Yes, it's an interesting theory, but it's bunk.