Get Out of Jail Free: Monopoly’s Hidden Maps

During World War II, as the number of British airmen held hostage behind enemy lines escalated, the country’s secret service enlisted an unlikely partner in the ongoing war effort: The board game Monopoly.

It was the perfect accomplice.

Included in the items the German army allowed humanitarian groups to distribute in care packages to imprisoned soldiers, the game was too innocent to raise suspicion. But it was the ideal size for a top-secret escape kit that could help spring British POWs from German war camps.

The British secret service conspired with the U.K. manufacturer to stuff a compass, small metal tools, such as files, and, most importantly, a map, into cut-out compartments in the Monopoly board itself.