While it's slightly possible that we may have been visited by extraterrestrials in the past, I strongly doubt humans had spacefaring technology before the 20th Century. And while I do see strong evidence for Atlantis (Gateway to Atlantis by Andrew Collins was very informative on this subject, although it's the only book of his you should trust), and other sunken lands/cities worldwide (hell, we got hundreds), I can say with complete certainty that "Lemuria" and "Mu" are complete crap (well, maybe not Mu, but it was more like an extension of tha asian continent if you ask me). As for teh Nazca lines (which are being horribly desecrated and destroyed as we speak), There seems to be two sets of lines: One, earlier set of geometric lines (very straight), and a newer set of animal shapes). I'm not sure what was going on here (and due t olack of care for this monument, we probably never will), but It seems that the newer lines might have been placed to honour gods of some sort. Again, I'm not sure.

Come to think of it, I think I have a map of these places somewher on my computer that I made, although i'm not sure........