Build it one story, in two rows, close both ends with a road down the middle. Put land mines on each side for 100 yards. Put chail ten foot link fence outside the mines.
Workable?
You wouldn't need mines, just guard towers every 100-200 feet along the wall, staffed with armed guards carrying M-14's. Night vision goggles or FLIR wouldn't hurt and some ground penetrating radar to detect tunnel rats would be a plus.
--Boot