It turns out that asking the question, "Have there been previous human civilizations on Earth" is not just crackpot goofiness.
If you are a diligent scientist, it forces you to ask some interesting questions, and look at human history in a different way.
I love this. Science done right.
I submit to Hubski the site of Gobekli Tepe. Old when the Pyramids were being built, it massively changes the narrative surrounding early civilization and our ability to make mega structures.