An illustrated story of the relationship between mapping and secrecy, charting the role maps played in concealing and revealing knowledge across centuries. Is there anything more intriguing than a secret map? One that reveals clandestine information or meanings, or a map that is itself a secret? Secret Maps features over one hundred examples of these kinds of maps, connected by their varied relationships to secrecy, and ranging from the twelfth to the twenty-first centuries and across the globe. They include views into state secrecy and power--such as maps used for domestic and military purposes, imperial expansion, espionage, and surveillance as well as those with private or commercial uses, such as charts of private land, trade routes, or the flights of private jets. The maps span widely in their scope and cover issues of broad interest, from old-fashioned spying to contemporary concerns about technology and privacy. As illuminating as it is thrilling, Secret Maps unearths the once-hidden routes, landscapes, and locations that have covertly shaped our world.