I happened to see the Puma Punku site on youtube just a couple of days back. I feel that there is a lot which is to be thought of and understood there. For one thing one cannot underestimate the capabilities and technological abilities of ancient civilizations. Secondly I do have a very exceptional view about such things as large stone blocks lying at great heights. I sometimes feel that most of the large stones actually were by nature at the same height; what the ancients did is just cut and dispose off the stone beneath them and make it seem that they actually lifted and kept that large block there at a great height. This is possible.