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.
A totally not serious answer. Today, I was sitting across from a Starbucks and staring at the logo. It is really weird. I started thinking that if something were to happen to civilization, all these cups, sleeves, merchandise and plastic stir sticks emblazoned with the Starbucks logo may cause future archaeologists to think that we worshipped some half fish woman thing (or whatever the logo is supposed to be).
Alternatively, this xkcd could be fun to do.