This is a sample partial entry from my current app London Travel: a Guide to Great Day Trips. The complete app for the iPad and iPhone may be downloaded at Apple's iTunes app store. This app takes you to many unusual places with daytrip range of London, along with the popular favorites. It is also available for ANDROID devices under the name London's Backyard.
Enigma: Something That is Not Easily Explained or Understood
Many of the deepest secrets of World War II are revealed at this rather nondescript estate north of London, where British and American cryptographers decoded the most sensitive Nazi and Japanese communications and played a critical role in the ultimate Allied victories.
Military history buffs will love this place, as will anyone fascinated by computers. Not only was Bletchley Park a top-secret intelligence center, but it was also home to the world's first digital computer, which has recently been replicated.
This is also the best place to learn about the fabled ENIGMA machine and its big brother, the LORENZ — Hitler's secret weapons that could have won him mastery over Europe had not the specialists at Bletchley done their jobs so well.
Bletchley is part of the modern "New Town" of Milton Keynes, created in 1967 at a point midway between London, Birmingham, Cambridge, and Oxford. Unlike other destinations on this app, it is not configured as a suggested tour since everything is in one place.
Trains depart London's Euston Station (EUS) frequently for the 40-minute ride to Bletchley (BLY), with returns until late evening. Avoid the slower ones requiring a change at Milton Keynes. Bletchley Station is very close to the estate.
By Car, take the A5 north to the A4146 exit marked Bletchley/Fenny Stratford. At the next big roundabout make a left onto a dual highway. When you pass under a railway bridge, follow signs to the Railway Station, making a right onto Sherwood Drive. Bletchley Park is on the left shortly. It is about 60 miles (97 km) northwest of London. Onsite parking is £3.
Touch photo in upper left. It will then fill the screen and morph into a DIAGRAM MAP. Touch that to remain on screen, THEN slide a finger from right to left to see more photos. Touch in upper left to return to text.
The National Museum of Computing, also on the same grounds and same admission ticket, is open only on Thursdays, Saturdays, and bank holidays, from 1-4; and also on guided tours on Tuesday and Sunday afternoons. Some parts are open daily.
Visitors should wear sensible clothes and footwear as some outdoor walking is involved. There are no restrictions on photography or videoing.
A full range of meals, snacks, and drinks are served at The Café in Hut 4, a restored WWII codebreaking location. There are also a few pubs nearby on Buckingham Road.
Begin at the Block-B Exhibition Centre, housed in an original wartime building. This is where you can get a good introduction to the process of communications interception, decryption, translation, interpretation, and analysis — the very heart of intelligence gathering that was so vital to winning the war.
Surely, the most famous item here is the Nazi Enigma machine, an electro-mechanical device that uses a series of rotating wheels to scramble plaintext messages into incoherent ciphertext. There were billions and billions of possible combinations, so the system was considered to be absolutely secure to all except another Enigma machine with exactly the same settings.
There was a weak point point, however. Any letter of the alphabet could represent any other letter, EXCEPT itself. That clue, and work done by Polish mathematicians before the war, enabled the Bletchley codebreakers to crack the Enigma code early on, giving the Allies a big advantage that probably shortened the war by two years and saved countless lives.
Much of the Enigma codecracking was done on the Bombe machine, developed here by mathematicians Alan Turing (considered to be the "father" of digital computing) and Gordon Welchman. Some 200 of these were built, and all destroyed after the war for security reasons. One has recently been rebuilt at Bletchley.
There are displays of similar machines dating from the 1920s to the 1970s, from Britain, U.S.A., Russia, Sweden, and Switzerland.
To see the rest of the trip, with photos and maps, take a download of the entire London Travel app into your iPad or iPhone on Apple's iTunes app store. Here's all the places it takes you to: