Whenever a place, a direction, or a route cannot be described clearly in words, people resort to drawings. Historians can learn a great deal about a society from the way it chooses to produce such drawings, which we usually call maps.
   The oldest surviving maps are clay tablets and papyrus remnants from Babylonia and Egypt. Called cadastres, they are sketches of property lines, showing where one person's property ended and another's began. The survival of these maps from 4,000 or more years ago indicates how important it was in ancient societies to define exactly the property that a person held.
   Cadastres were based on careful observation and some mathematical skill. The same was true of another kind of drawing, the chart. Charts were often produced by travelers, either to show the route from one place to the next or, more commonly, to guide sailors at sea. A chart would show the shoreline, indicate the location of dangerous rocks, and help a ship's captain navigate along a coast. Charts became especially useful during the 1400's, 1500's, and 1600's, when overseas exploration became important.
   When people could not observe directly, they had to estimate and use mathematical projections to create what we now recognize as maps. Mapmakers used such estimates to create maps of their countries and of the world. What they showed tells historians a great deal about their altitudes and beliefs. Christian mapmakers, for instance, often showed the holy city of Jerusalem as the center of the world. The Dutch, on the other hand, liked to make maps with the west, instead of the north, at the top. In this way the seacoast of the Netherlands was at the top of the map. Distortions sometimes revealed the hopes of explorers who thought, for example, that it would be easy to sail around the northern part of America. Maps were also made of mythical places like Thomas More's Utopia.
   Only in modern times has accuracy in map making improved greatly, as a result of surveying techniques and aerial photography The very accuracy of our maps also tells something about us—that we live in a scientific age.