9 There was no iron in the Americas. Yet Zahi Hawass claims Puma Punku, Teotihuacan, Texas rockwall etc were built using obsidian, copper and bronze tools. Bird chirps when you clap Chichen Itza? 2300BC no tin or arsenical bronze but Zahi claims copper +bashing stone are enough for 13Mton Giza Complex (media.conspiracies.win) posted 1 year ago by defenderOfMontrocity 1 year ago by defenderOfMontrocity +12 / -3 18 comments download share 18 comments share download save hide report block hide replies
https://www.ancient-origins.net/artifacts-ancient-technology/cut-stone-lost-technology-ancient-021545
Aside from that:
Professor Michel Barsoum and colleagues have found scientific evidence that parts of the Great Pyramids of Giza were built using an early form of concrete, debunking an age old myth that they were built using only cut limestone blocks.
https://drexel.edu/engineering/academics/departments/materials-science-engineering/about/special-projects/engineering-the-pyramids/
Limestone is nature's concrete. I can see an issue distinguishing between the two hundred of years later.