In 2003, the U.S. Library of Congress paid $10 million for the first map in world history to use the name "America." The map goes on display in Washington this month, but researchers remain puzzled by its startling accuracy. Produced in 1507 by a German monk named Martin Waldseemüller, the map estimates South America reasonably well and even includes a large ocean to the west—years before the Pacific was discovered. Here, 500 years after its creation, is the famous Waldseemüller map:

U.S. Library of Congress

And here's what it looks like up close:

U.S. Library of Congress