The British Army had abandoned most of its equipment in France after the Dunkirk evacuation. It was therefore decided to build a static system of defences which could delay the Germans long enough for more mobile forces to counter attack. The defences were made up of around 400 concrete "pillboxes", anti-tank obstacles, trenches and minefields which took advantage of natural and man made features. The main line of these defences was known as the GHQ Stop Line.
Over 100 pillboxes on the Line can still be seen (2003).