As it says in the introduction, it's amazing that any of the images and documents which have been replicated in this book still exist, such was the secrecy surrounding Bletchley Park not only at the time, but also in the decades which followed the war. There's a lot more to this book than just cracking of the Enigma code. The book details the whole history of the house from its construction up to the present day, Bletchley's important role at the 'dawn of computing', and how the codebreakers both at Bletchley and its stations around the world helped crack many different German and Japanese codes. The people who worked there are also brought to life through many curious little personal details, such as one female codebreaker drying her underwear on top of the Colossus machine, and Alan Turing chaining his mug to a radiator to stop people stealing it! Packed with photographs and removable artefacts, this beautiful book is well worth the money. It's an entertaining and vibrant book and I can't recommend it enough.