Example: Great Pyramids of Gize were not build by Egyptians, even Aristoteles and Plato wrote, that the Egyptians told and showed him, that they inherited those monolitic structures with the math to that and they are bound to preserving them. There are some quite good engineers from different disciplines who all say, that this is not possible with bronce chisels and stones, hence material used in the pyramids and southern America is near adamantine and much, much older (in the six figures) then stated. Even modern techniques of building are not near to the precision of the pyramids, despite a lot of engineers tried to rebuild those structures and all failed even with modern tools.
My two cents for that