Field Marshal Erwin Rommel was in charge of the wall. He improved the defences of the entire coastline. Steel obstacles were put on beaches, concrete bunkers and pillboxes constructed, and low-lying areas were flooded. Pointed stakes were set up on likely landing grounds to make it hard for the Allies to do airborne landings. The Germans fortified the foreshore area as part of their Atlantic Wall defences (including tank turrets and barbed wire).