Really neat find, thanks for posting this! I hadn't seen this before. Its a map of a previously unseen-by-the-general-public Aztec manuscript, recently coming into the possession of the Library of Congress. Lots of good stuff on their website about it too. Spoiler: pics Just in case you don't want to go to the link. The Aztec map: Modern-day Map of the land the ancient one covers: Close up: