Oh come on. We all know that it is more likely that space aliens came here from light years away and built it.
I think the stone henge is built in just the right location... that the builders harnessed the power of the earth giving them super human strength to lift those massive blocks into place theoretically it could have been just 1 person who built it.
I dunno they didn't show that part, but the did show a part of the dudes own henge thing. He had 3 1 ton blocks, two supports and one beam, all stacked up by his own hands, so I dunno, figure it out, he did My guess: they jacked up the beam equal to the height of the two supports, then they rolled it like he was doing in the beginning with the smaller blocks of like 1600 lbs... Maybe not possible to do with one person, might need a good bit of umph to get it rolling initially. Is there anyone else here who would love to experiment with this? I kinda wanna make my own mini stonehenge lol.