The least expensive and most efficient wall to stop or at least, curtail over the border traffic on any border was the Iron Curtain.
It was not even a physical 'wall'. it was combination of land mines and watch towers every 200 yards manned by eager marksmen ready to shoot and ask questions after.
Learn from history.
Are you serious with this mines-that-blow-up-people-into-chunks this or is this some sort of retarded joke?
No joke, Worked eminently for the Soviet regime. No denying that.
As I said, learn from history.
Local coyotes and vultures also need to eat.