What is Bletchley Park?
Bletchley Park is a country house and estate in Buckinghamshire that was the center of British codebreaking during World War II. Codebreakers there broke German Enigma messages, helping the Allies win the war.
The British government bought Bletchley Park in 1938 to house its codebreaking operations, the Government Code and Cypher School.
Thousands of people worked there during the war, including mathematicians such as Alan Turing, linguists, chess champions and crossword experts. Many were women.
Breaking codes
The codebreakers used machines called bombes, designed by Turing and Gordon Welchman, to decode Enigma messages. Colossus, one of the world's first programmable electronic computers, was used to break the German Lorenz cipher.
The intelligence gained, known as Ultra, helped the Allies in the Battle of the Atlantic and the D-Day landings. Some historians believe it shortened the war by up to two years.
The work at Bletchley Park was kept secret for decades after the war.
Today, Bletchley Park is a museum where visitors can see the huts, rebuilt bombes and exhibitions. The National Museum of Computing, on the same site, displays a working rebuild of Colossus.