If you are the kind of person who would rather have their toe nails extracted without anaesthetic than traipse round a country house, then Bletchley Park is for you. You don’t go there to envy a life style; you go to learn. Built in 1883 by financier Herbert Samuel Leon in a mock pompous, vulgar style and due to be demolished in 1938, it was saved by the Government as HQ for the code breakers, the Code and Cypher School. Close to the main railway line, which had the main telephone cables running alongside, and near the A5, it was perfect for communications.

The surprise about the park is that there is more than the code-breaking and computers commemorated, there are also tanks, radar and electronics, Churchill memorabilia, military vehicles, fire engines, cinema projectors, everyday life at Bletchley during the war, toy and model railways.

At the moment the place is run by the kind of people who have never heard of leisure, tourism and heritage, and would never want to. They are volunteers and have something far more important, a passion. The whole place reeks of the Forties, from the John Bull printing sets to the ration books. It is a national treasure house of attitudes, aptitudes, memorabilia, artefacts and technology. Most of the exhibits are owned by the people who stand at the side of them and they will talk with the kind of expertise that cannot be bought or scripted.

The amazing thing is that this unique, important site was almost demolished in 1991 to make way for housing. This is the place that Churchill said:

“laid the Golden Eggs and never cackled”. The breaking of the Enigma code and the cracking of the Lorenz code are just two of the important events that determined the course of the war. Alan Turing, one of the most profound thinkers of the last century, worked here and it was his team’s work that took the covers off the enemy strategy.

The fact that the US and the UK knew the enemy strategy for most of the war gave allied forces an enormous advantage. The Enigma code was broken and most of the effort at Bletchley was in obtaining the oded messages, decoding them and transmitting the results out to those who mattered. Speed was ultra important.

You will hear the story of Tommy Flowers, who sounds like a man with a cloth cap who sells hot chestnuts at the side of the street in Piccadilly. He wasn’t; he built the first programmable computer, the Colossus, to crack the Lorenz codes which revealed the location of the German divisions guarding the channel. After the war, he was not allowed to discuss his work, and the computer he designed was a secret until 1970. Most of the Colossus machines that were constructed were destroyed in 1946. Even its decryption algorithms are still a state secret. How was Flowers rewarded? With obscurity, pound;1,000 and an MBE.

Tony Sale, a computer historian, has devoted the last few years and a great deal of his own money to re-building the Colossus with little more to go on than a few photographs and reminiscences. The original plans had been destroyed by government order. The rebuilt Colossus looks like the kind of machine used in early science fiction films. Sale is understandably proud of it, and claims its speed of computing is just below Pentium level, not bad for a computer from 60 years ago.

Bletchley Park did not win the last war single-handed; it took a lot more than that. Nevertheless, a great deal of what we take for granted now started life here. “Lara Croft and virtual newsreader Ananova really came out of the work in Bletchley Park”, claims trust director Christine Large. In one phrase she gives the Buckinghamshire estate a crucial role in feminism and information technology.

Peter Westcombe, one of the guides, and one of the people who led the campaign to save the place is in no doubt about its message, “What this place should say to children is: brains overcome brawn”.

Jack Kenny is a freelance writer and chair of examiners for English for one of the major GCSE examining boards

Opening times: Bletchley Park is open at certain weekends (see website for details) at 10.30am to 5.00pm, last admission 3.30pm.

Admission: pound;4.50, concessions pound;3.50, charges may vary for special events. The Bletchley Park Trust, The Mansion, Bletchley Park, Milton Keynes, MK3 6EF. Tel: 01908 640404.www.bletchleypark.org.uk