Bletchley Park was the central site for British codebreakers during World War II. It regularly penetrated the secret communications of the Axis Powers – most importantly the German Enigma and Lorenz ciphers. The official historian of World War II British Intelligence has written that the “Ultra” intelligence produced at Bletchley shortened the war by two to four years, and that without it the outcome of the war would have been uncertain. Located in Milton Keynes, Bletchley Park is now a flourishing heritage attraction.