Modern sculptors who create massive public art pieces have a hard time moving their works across town to the display site without using heavy equipment and a crew of individuals with strong backs.
Which is why it's hard for modern people to imagine how the ancient residents of Easter Island moved those massive Moai heads from one side of the island to the other without the aid of machines.
This question of how ancient people moved massive stuff prompted students at MIT to build the McKnelly Megalith to prove how easy it can be to move a massive object with a minimal amount of force:
The structure was built over the course of a few weeks using fiber-glass enforced concrete and a soft foam core. At 2000 pounds, it’s considerably lighter than the 82-ton Moai of Easter Island, but the fact that it can be adjusted with just the push of a finger is still an extraordinary feat.
Megaliths like MIT’s structure and the Easter Island statues are specially designed to be rolled or shimmied across long distances using carefully calculated movements. As long as the center of the object’s mass is positioned in just the right place, it should be able to be moved with relative ease regardless of its weight.
The way this method could have been used on Easter Island close to 1000 years ago is detailed on MIT Architecture’s website: "In a similar manner to how one might shimmy a refrigerator into place, the Moai were pulled back and forth by ropes, employing momentum to transport these unwieldy megaliths. This (re)discovery brings new meaning to the folklore that the statues 'walked themselves.'"
MIT’s megalith was erected in a similar fashion. At a rate of about 300 feet per hour, a small team teetered the piece to its final position and then hoisted it upright using a rope.
-Via Mental Floss