In pictures: GCHQ's new HQ

1 of 7 The Government Communications Headquarters, alias GCHQ, home of Britain's intelligence-gathering operations is on the move.

2 of 7 The spies and boffins are bidding farewell to their offices in more than 50 small buildings across Cheltenham...

3 of 7 ...and moving into the "doughnut" - a new £337m complex in the Gloucestershire town.

4 of 7 The new building, designed by British architect Chris Johnson, has taken three years to build and will house 4,500 staff.

5 of 7 Its open-plan design is aimed at improving communication between workers in the notoriously secretive government department.

6 of 7 A glass-covered "road" around the middle of the building brings in light and will house shops, cafes and even a hairdresser.

7 of 7 And in the "hole" in the centre of the ring-shaped building, a landscaped garden will give staff a place to take breaks.