During April 2015, during my latest visit to London, I spent one morning in Bletchley Park, "once Britain's Best Kept Secret" as they call it. Bletchley is about 1 hour by train from London, on the north. The place has become very popular after two events in 2014 (I do not really know if one influenced the other):
One of the more than 20 ENIGMA machines -looking brand new
- The "Imitation Game" movie that went the most popular movie about the story of Alan Turing and the codebrakers of the second world war
- The complete restoration of the place, which opened for the public at the beginning of 2015 (Bletchley was there before, but without the restoration there was not much to see).
So, is it worth the visit ? (the entrance is around 15 GBP, the ticket might cost another 15 GBP and you will need 4-5 hours at least). My answer is yes. The visit will give you some unique insights in the ENIGMA machines, the code-braking techniques and of course the Bombe ! (this weird mechanical computer, that was used to find the positions of ENIGMA wheels based on intercepted messages).
Also, you will able to see not one, but actually two Bombes (Not originals - as all of them were destroyed right after the end of the war. Or at least this is what the British Government said at the time). One was made for the needs of the Imitation Game movie (it does not seem to work, but is a very well-made replica) and a full-functioning replica made by the Bletchley park and collaborators.
With the working replica of the Bombe
Another nice opportunity for the visitor is to see all the restored offices and warehouses of the centre, as it was during the war. You can also have a seat in Alan Turing's office !
Working at Alan Turing's office at Blechley Park
A nice add-on is the near-by National Museum of Computing, where at an extra cost yo can see the remake of the allegedly first-built electronic computer / Colossus (built in 1943, before the ENIAC in US).