Without a map key, some maps would not be able to be understood at all! The symbols found in the legend, or key, tell what resources a place has, how a country's borders have changed over the course of its history, and so much more. In this helpful book, readers are introduced to common map key symbols and learn how they can be used on all kinds of maps, from political to physical maps. Full-color examples of maps with simple keys help readers apply their new knowledge immediately.