This is graveyard related, so if you find this upsetting, please be warned.
I have wandered through many a cemetery in my time, and mostly the graves are from the 1800s onwards. In churchyards you might get something dating back another couple of centuries. In cathedrals and the like you mind see the graves of 'important people' from much earlier, but only the important people.
Where is everyone else? Presumably in unmarked graves, but where? Is the concept of one cemetery where everyone from the town is buried, and their grave marked out, a modern concept? Are people buried all over the place?