Comments by "Paul Frederick" (@1pcfred) on "Set: The History of Concrete" video.

That's a lie. The main ingredient with Roman concrete is Italians. I don't know what it is about guineas and masonry but there's some definite connection there. We did a job with Italian marble and we couldn't even buy the marble without Italians coming with it. They insisted. I swear they came right over on the boat with the slabs. It was like they were married to them rocks. Not a one of them spoke a word of English either. They knew how to set stone though.
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The Great Wall of China is 5,500 miles long and was not constructed the same along its whole length. Different parts are made out of different materials depending on what was available locally. Today I think there's really only one famous section of the wall the tourists go to. But it never all looked like that. The logistics of heavy construction were pretty challenging hundreds of years ago. They had no big heavy trucks they could just load up with materials after all.
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