Have you ever seen a pillbox? If you’ve driven around the country the answer is probably yes. Many roads pass these little concrete bunkers left over from the wall.
Do you know what pillboxes are? Many of us know these were places for soldiers to shelter from gunfire while being able to shoot back.
Do you know why they were built? Often the clue is in the location of a pillbox, overlooking a road or abridge, even a river or railway; the pillbox would have been to stop the enemy from going any further.