seriously guys, i would be the first who wants it that aliens already visited us and helped us build stonehenge and the pyramids and whatnot.
the main starting point for all these theories is our own perception of superiority. we think that only white westerners are able of technical, social and intellectual prowess.
fact is that there were tons of intelligent people out there living at all times. also, there might have been certain social structures that allowed priests or kings to build huge things. whenever youre not fighting for survival 24/7, you have enough time to build something like stonehenge.
you could build it like ancient greeks or egyptians built their huge temples. noone is questioning how the greeks were able to construct huge columns, why? well they simply "buried" the current progress, so that the next piece of whatever was put on top could be inserted at ground level, and not lifted several dozens of feet in the air. furthermore, its not outlandish to think that even ancient cultures had simple cranes, hoists and other tools.
refer how a much bigger piece of stone (obelisk from nero's circus) was erected in a, compared to today, extremely primitive way.
egyptians simply put the obelisk on a sand bed half the height of the obelisk itself. (neglecting some supporting elements,) they, in principal, simply dug out the sand on bottom half until it stood vertical.
we are technologically advanced, yes, but its a shame to discredit the genius and physical sacrifice of ancient tribes, just because we think there never was anyone capable of doing anything overly impressive.
in all seriousness, i read that 3 times, 1st time i thought what the fuck is he on about, read it again and thought, this fuckbag has to be kidding, read it once more and decided calling you a fuckbag wasnt good enough - sick-as-aids