SHROUDED in secrecy for decades, Bletchley Park was the beating heart of the Allies’ codebreaking operation– and where, many contend, the war against the Nazis was truly won.

It is the place where Alan Turing broke the Enigma machine; a momentous breakthrough which would lead to the victory against the Nazis’ reign of terror.

But he did not carry out his painstaking work alone. In fact, thousands of codebreakers, linguists, and mathematicians travelled to Bletchley every day on a mission to pre-empt the enemy’s military operations and bring fascism to yield.

This is the fascinating story of the apparently inconsequential Buckinghamshire stately home, which has only come to light in the last 40 years.

Strolling from one hut to the next, presented as they were, coats and hats hanging from their hooks on the wall, desks strewn with undecipherable German messages ready to be decoded, the magnitude of the codebreakers’ round-the-clock work is immediately impressed upon the visitor.

Quotes from codebreakers themselves inscribed on the walls give a striking insight into the enormity of their daily task – one mistake and thousands of lives could have been lost in an instant.

Their commitment and devotion to their country is felt by each visitor, who would now be leading very different lives were it not for Bletchley. After all, it is in these very rooms that the breaking of the ciphers of the German Secret Intelligence Service allowed the British to confuse Hitler over where the Allies were to land.

Bletchley Park also heralded the birth of the information age, with the industrialisation of the codebreaking processes enabled by machines such as the Turing/Welchman Bombe, and the world’s first electronic computer, Colossus.

A visit to Bletchley would be sorely incomplete without a guided tour. Our guide, a distinguished man in a dapper suite by the name of Bob and bursting with enthusiasm, truly brought Bletchley Park, its key players as well as the thousands of souls who remain in the shadows to this day, to life.

His inexhaustible catalogue of anecdotes, step by step explanations of how the Enigma and Bombe machines encrypted and deciphered intelligence and historical facts, left us all hanging on his every word.

I would have happily followed him around Bletchley all day if he let me.

One of Britain’s best kept secrets, it is a historical treasure which determined the lives of generations across the globe. Ask for Bob and see for yourself.

Bletchley Park is in Milton Keynes, postcode MK3 6EB. Admission costs £15 for adults, £9 for children 12 to 16 and children under 12 go free.

Winter opening times (from Nov 1 to Feb 28) are 9.30am to 4pm. For more details go to www.bletchleypark.org.uk