Ooooh, I think I should probably clarify the info a bit. xD
By remnants of old cultures I meant it more in the sense of...kinda like what archaeologists dig up today. You might find a fairly well preserved item if you're lucky, but most stuff has just been lost to time and reclaimed by the wild. Radiation is no longer a factor, either, since it's been so long, and, well, most of the buildings have just decomposed or been lost entirely to shifting landmasses, the oceans, etc., or just wind up as rubble that's now buried under dirt and grass. Modern-day buildings aren't really built to last.
It's been a reeeally long time since the continents have shifted and changed so dramatically. xD Of course, this Earth is pretty alternate universe since there's magic and elves and stuff, but yeah.
Basically, you'd be lucky to find a skeleton structure. You'd be more likely to find broken up scraps of metal that look like they go to something, and wonder what it was. Connlaoth might have gotten some of its technology by finding a fairly well preserved gun and studying it, for example. ^^ There were also probably some survivors from the past, and through them some of the ancient things survived--but over time were modified, absorbed, and became something entirely new as the world and its people rebuilt. That's why some modes of dress may have some influences similar to stuff that existed before, though it's been changed a lot and hardly even resembles what it once was. And now entirely new cultures exist.
So it's there for a little flavor so the people of today know there was SOMETHING before them, something that was destroyed and probably was bad, but there's just not much left of it, and it's not really the focus. x3 The focus is on the countries that exist now!