You know, it just occurs to me that, given enough thousands of people in between,
A) a lot of evidence would have been destroyed, or no longer translatable, so just about anything you find in an area may lack anything to corroborate or disprove it, and
B) for lack of either, a lot of that stuff gets taken as actually representing some local custom that someone just confabulated from a few faded images on a wall.
I mean, like how we see depictions of some people apparently playing leapfrog or something with bulls, and we go, "it's believed to depict a local religious ceremony". And not, for example, "it's believed to have something to do with some completely mythical story from that time." Sometimes even stuff from fiction sagas, like that someone got a coat as a reward, are interpolated as "oh, it means they had devolved from a money-based economy to barter."
So my... well, half-way fear and half reason to giggle is that after a couple of dark ages and even more thousands of years, someone will find the first pictographic records from the great ancient American (or German, or whatever) civilization: someone's massive porn stash
Just think about all the things they could learn about how our society works.
Or I suppose it could just end up in an art museum and valued millions of whatever currency they're using. I can just see it, "And to the left you see Larry Flint's newly discovered masterpiece. We tentatively call it, 'Venus with still life up the ass.'"
