Is this one of those things were it ends up aliens had to have helped our ancient ancestors do all this stuff? It's chauvinism to think we are so advanced and our ancestors were too stupid to do great things.
I agree, mostly; some of the specualtion is clearly just weird, but that doesn't make a lot of the mystery any less awesome and admirable. It's proof of what cultures can achieve if they had long enough perioods of peace and weren't having to worry about being invaded and looted by foreign warlords all the time. They only thing in modern history that approaches that sort of peace for many countries, especially in the West, has been technological advances and nuclear weapons.
