I like maps of how old scholars viewed the world because they are 1) simple and 2) alien while still being familiar. There are also several of them, so you could use them as alternate prime material planes or whatever. I found a few nice ones in the Library of Universal History and Popular Science (1910). Here is the oldest and simplest map:
my printing adventure I'm trying to trace this one into an svg, but I'm still learning that process. (I promise when I figure it out I'll post a tutorial). These are both public domain and if you can use them, please do.