The lightest stones used in stonehenge, they come from 250km away... And their weight goes up to 4 tons... I let you imagine what it's going to be to move them around with the little wooden rail under it, and in mud and shit, 4 to 5000 years ago... (because that's how old that thing is, it largely predates jesus christ... By some 3000 years or so...) Now the heaviest ones, the so called "sarsens" are 9 meters tall and weight around 25 tons.... Good luck with that