Just a thought I've had while reading this reply: Maybe you don't need to really make the areas beyond? As in, you could use the trees and rocks, as talked before, but you could also use some kind of fog, that get's stronger and stronger until you can't see much, meaning you'd only get vague outlines and it wouldn't stretch as far as the player can normally see with the angle. It's also possible to make it some kind of picture that changes slightly with the angling, but this could be hard to do, dependind on methods. I still prefer the smaller rooms, but just throwing ideas your way.