The once top secret Post Office at Bletchley Park has released its one hundredth limited edition stamp sheet.
The tiny but historic post office was once the undercover mail room for Allied code breakers during the Second World War. Its first limited edition stamp sheet was issued in July 2005 and featured a Second World War Enigma machine. Acquiring one of those now will probably cost in excess of £425, 17 times the original issue price.
The latest issues feature Bletchley Park’s iconic mansion and the post office, and can be viewed online at bletchleycovers.com