I feel like it's the Pyramids.
Also let me tell u a cute story.
At my work there is this Egyptian guy, who is really cool and funny I really like him and me and a friend asked him about the pyramids and **** and he said that for the people in Egypt it's actually not that big of a mystery. I mean he says that it's impressive indeed, but you know what he told me ?
He said that they just used the SAND and they were basically building the pyramids as if they are in a hole. Imagine just building the sand high on each side of the piramyd so they can reach higher and higher. And when the sand is wet it can be really hard u know...
He said that it was like they were building the pyramids in a hole. And it makes so much sense

I mean it's still impressive and ****, but yeah, after all, the Pyramids were discovered under the sand u know...
And yeah they used some kind of mechanism to lift the cubes... like you've seen in the movies.