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You can find a bunch just by doing a bit of searching -- Damascus steel, Zhang Heng's seismograph, etc. Be careful though since there is tons of quackery out there. One thing I learned -- the blocks in the pyramids that everyone is mystified about are nowhere near the biggest
blocks used in ancient constructions; there are some that are 10x bigger! (That were not moved nearly as far as the Khufu pyramid blocks, but, still ... )
