After the war GC&CS changed its name officially to GCHQ and moved its Headquarters to Eastcote in Middlesex (1946) and later to Cheltenham (1950s). But the Central Training School stayed at Bletchley Park until 1987, when it moved to Culmhead (near Taunton in Somerset).
However, most training on the BP site was done for the telecommunications branch of the GPO (later, British Telecom). Their trainees learned the skills needed as radio operators on the various civil HF services provided by the GPO until the late '60s, when satellite and later high-capacity cable and microwave links started to supplant these. The administration, and eventually the land title, of the BP site passed from GCHQ to the GPO. When BT was privatised the site became a BT corporate asset, while BT's need for its training facilities was rapidly decreasing.
The entire site (apart from the Listed mansion), including all the wartime GC&CS buildings, was in danger of being sold for development, and substantial parts were. However, a group of enthusiasts set up the Bletchley Park Trust
which saved the central part of the site. This has developed into a major heritage site commemorating the work done at BP during WWII. Two of the trustees are former senior members of the GCHQ Board.
GCHQ has supported Trust-sponsored construction of working replicas of both of COLOSSUS and of a Bombe, and is supporting work on the building of a reconstruction of DELILAH, a post-war secure speech system.
The Bletchley Park Trust preserves part of the history of British Sigint. GCHQ supports the Trust by providing significant numbers of artefacts and documents for display. Members of staff new to GCHQ visit Bletchley Park as part of their induction process to learn something of the skills and values of our predecessors. The innovative and inspiring work of Bletchley Park remains a n inspiration to all who work in Intelligence.