Directions in a recent Monitoring Times (not MY column!) on how to get there from London appear to be erroneous. Long time contributor Ken Maltz writes about how he made a recent trip:
... coming up from London, Bletchley is a local stop on the National Rail system. Either take a local train to Bletchley or take an Express train to Milton Keynes and then a local train southbound for just one stop to Bletchley. Once you get to the Bletchley station, there are signs directing you to Bletchley Park; less than a 5-minute walk.
My own visit to London, including a day trip to Bletchley, is a few weeks off. Research has confirmed that Ken's directions do seem to be accurate. There are something like four trains per hour, one of which is an express and stops only at Milton Keynes, so you change trains. Either way, you end up at a station very close to Bletchley.
There's a lot there. More after I see it!