This slideshow covers some interesting mapwork -- from the earliest suspected map-like drawing to topographically inaccurate maps to those based purely in fantasy.
"During the Age of Discovery, explorers plotted islands and continents where none existed. First, writers, and later, propagandists, discovered that a fake map can lend legitimacy to wild ideas. Maps are more than 2-D renditions of 3-D topography. They can, and often do, express complex fantasies."