One way writers, filmmakers and game designers give depth and richness to the worlds they create is by laying those worlds out on paper—such as with these renderings of worlds like Middle-earth, Narnia and Gotham City.
Doesn't matter if it's science fiction or fantasy, comic book or videogame—maps are an important part of establishing the rules of the fiction you're dealing with. Where the characters exist is crucial in conveying who they are. After all, no man is an island, even if he lives on one.
Hit up this Tumblr site for reams more arcana.