Explanation first. The GHQ Line [General Headquarters Line] was a defence line built during World War II to contain an expected German invasion.
The defence line comprised hundreds of concrete pillboxes and anti-tank defences. Here in Surrey Heath we are above the GHQ Line- see map below – though we do have a smattering of pillboxes, notably one on Deepcut Bridge Road at its junction with Old Bisley Road. As ever, wonderfully, there’s a group of people dedicated to their preservation – see the Pillbox Study Group website.
Chris Kolonko, a military heritage specialist, in his Mapping the GHQ lines in Google Earth, provides the necessary detail on the location of each of the defences. Here’s a screenshot from one of his maps. If you’re interested, you’ll find much more to discover on his maps.