During World War II, The United States Playing Card Company joined forces with American and British intelligence agencies to create a very special deck of cards. This deck was specifically created to help allied prisoners of war escape from German POW camps. This deck of cards became known as the “Map Deck.” It was made by hiding maps of top-secret escape routes between the two paper layers that make up all modern playing cards. When soaked in water, these decks could be peeled apart to reveal hidden maps that allowed escaping prisoners to find their way to safety. While these cards do not have that feature they do have a recreation of the map printed along the inner edge. The map can be created by laying each card down in order just as POW's would have.