About 20 minutes from the city center, the free National Cryptologic Museum features the work of spies and counterspies, as well as methods of encrypting strategic communications. Here, you can see the actual Enigma machine that enabled the allies to decipher German signals during World War II. Historic artifacts include everything from the most elementary cipher disks, code books, and encrypting typewriters to supercomputers. A scavenger hunt encourages children to decrypt messages and answer questions as they tour the museum. Guided tours last about 90 minutes and are filled with fascinating insights into the world of spies and codes, from the Code talkers of World War II to the role of communications in the Cold War and later. In the adjacent National Vigilance Park are two reconnaissance aircraft used for secret missions.