World War Two was won by soldiers, officers, sailors and air crew. But it was shortened by mathematicians. Had codebreakers not provided invaluable information behind the scenes, WW2 could have dragged on until 1947, or 1949, or we could even have lost. Hurrah, then, for the cream of British intelligence at Bletchley Park. Fancy a visit? It's easy to get there. The entrance to this former top secret establishment is within brief walking distance of Bletchley station. For those in London, that's a zip up from Euston station. Pick your fast train carefully and you could be walking through the front gates less than 45 minutes from leaving town.
Bletchley Parkmansion lies halfway between Oxford and Cambridge, which helps explain why MI6 officials bought up its estate immediately before the outbreak of war. They established the hastily-assembled Government Code and Cypher School, and erected scores of prefabricated huts around the grounds. Within these workspaces the brightest minds of the day (mostly men) were supported by a pool of devoted administrators (mostly women). Nobody ever mentioned to friends or family what they were up to, and Bletchley Park's secrets stayed hidden well into the 1970s. The site's now owned by a trust and has been open to the public since 1993. They maintain a series of exhibits and exhibitions, and attempt to prevent the place from crumbling into disrepair. Most importantly, they've so far managed to prevent the site from being redeveloped into a bog standard housing estate, like the one that's currently being erected nextdoor. So far, so good.
The German armed forces sent coded messages to each other using a fiendish machine called Enigma. This looked like a typewriter in a wooden box, with an electric current travelling from the keyboard through a set of rotors and a plugboard to light up the 'code' alphabet. Enigma could encrypt any message into code in over 150 million million million different ways, which led the Germans to believe that their codes were unbreakable and their military secrets were safe. They were wrong. Several different Enigma machines are now on display at Bletchley Park, along with a variety of other wartime memorabilia. Volunteers also run explanatory tours for visitors - ninety minutes around the site, mixing historical details with cryptographic technique. These deliver over and above what you might normally expect, and are led by entertaining experts. I think it's fair to describe the tours as intellectually stimulating, so if you find reading The Sun a challenge I wouldn't bother.
Hidden away at Bletchley Park, the cream of the UK's code-breakers were ready and waiting each morning to try to crack that day's code. There were useful clues, like the fact that messages often started with a weather report, or the fact that Enigma never ever coded a given letter as itself. One major advance came from mathematician AlanTuring, who designed a complex mechanical device called a Bombe which could analyse hundreds of thousands of possible rotor positions. Thanks to its input, Churchill often knew precisely what the Germans were up to and could plan his tactics accordingly. The original Bombes were all destroyed after the war, but volunteers have managed to reconstruct one and it has pride of place in the exhibition in Block B. The tour guides also have access to a more basic mock-up, and they'll try to explain to you how the rotating drums generated electrical circuits which identified logical contradictions. Don't leave your brain at home.
After the war ended the site passed into the hands of the GPO, and then to BT. There's still a mock-up PostOffice in the grounds, which was once used for training and now sells first day covers (and stuff) to visitors. Most of the huts have survived, in varying statesofrepair, and several are open for you to poke around inside. See Alan Turing'soffice in Hut 8, find out about Winston Churchill in Block A, or sample the (non-historic) cafe in Hut 4. There's a model railway exhibit in one (didn't you just know there would be?) and a collection of vintage vehicles in the lock-ups round the back of the Stable Yard. This weekend, as a special treat, the Bletchley Park site is dressed up for a "Festival of Christmas" event. Specially imported fake snow covers the front lawn, which is ironic because the real stuff only melted a few days ago. There's a (rather small) funfair, and a (terribly artificial) ice rink, plus an (obviously genuine) Santa Claus greeting children in Hut 12. More intriguingly the ground floor of the mansion has been taken over by 50 stallholders flogging festive gift fodder, from 'vanilla and chilli' candles to win-a-bottle tombolas. The event's reeling in the locals, but rather at odds with what more long-distance visitors have come to expect.
Bletchley Park is a fascinating place to explore, and the volunteers on site make every effort to be both helpful and informative. If you're the sort of person who reads this blog more than intermittently, you've either already been or really ought to go. Admission usually costs a tenner, but entrance is free this weekend if you fill in the voucher in Milton Keynes' local paper. Personally, I suspect they'd prefer you to wait. Given the perilous state of Bletchley Park's finances, every paying visitor counts.