Saw a post on X saying that the latitude of the Pyramid of Giza is the same as the speed of light.
I looked into this, expecting it to be approximately true. It’s exactly true in the sense that the speed of light in vacuum is 299,792,458 m/s and the line of latitude 29.9792458° N passes through the pyramid. The exact center of the pyramid is at 29.97917° N, 31.13417° E.
Of course this is a coincidence. Even if you believe that somehow the ancient Egyptians knew the speed of light, the meter was defined four millennia after the pyramid was built.
Scott Alexander has a nice short essay on this from long ago: https://slatestarcodex.com/2016/11/05/the-pyramid-and-the-garden/