How did they build it

[surada]

I can tell you've never built anything.

You're a stone mason?

 

[para bellum]

There are constraints here that you are overlooking. The "surfaces" or faces as we call them in geometry, are relatively fixed for each block.

One can have blocks with flat faces carved by hand, but the chances of a row of such blocks lying in a straight line is very slim and the chances of another row placed above that, also being a straight line is pretty much nil.

You'd have a very good point IF all the blocks were the same size and shape, but they are not.

They had stoneworking tools, they knew about lapping, it's not that amazing to me, given they had plenty of time and labor to spend.

Only the outer faces are tight fitting, they used fills and slurries to set the stones. The contact surfaces are not perfect fits. You can make a template for any irregular shape, and get a pretty close fit by matching the template. A little lapping and you are good to go.

Read the pdf I linked in post #9

Granite inspection plates are finished in pairs by lapping- even the cheap ones are flat within a few ten-thousandths of an inch...

 

[Muhammed]

pretty close fit

"pretty close"?

That is not good enough.

Feel free to ask any questions.