Been thinking along the lines of Planet of the Apes -but without any man made catastrophe, meteorite impact and climate stabilization- what sort of structures or evidence of our civilization would remain in five or six million years if we all just vanish? Would an intelligent species of evolved insects -or something else- find buried artifacts in the ground like we did the dinosaurs? Would ancient structures like the pyramids or Great Wall remain for that long, and would any modern things like the Eiffel tower, Burj Khalifa, or even some present day Doomsday Vaults survive that amount of time? In our digitized age, I assume that not much would remain, other than satellites maybe or I suppose any modern species that just happens to get preserved like a dinosaur did.
Literally nothing…
10-20k years left and the only thing left would be like Mount Rushmore and other giant stone monuments.
At 5-6 million years it would only be the layer of plastic in landfills from before bacteria evolved to break it down and nuclear test sites if the future society does isotope testing there. Both things that have much more logical explanations than an ancient civilization with no other evidence.