7. anti vehicle trench

This is a facility that obstructs an escape by car. They dig a trench about 1 meter deep and put concrete panels. When somebody tries to escape in a vehicle, it falls into the trench and cannot go ahead. No civil cars may drive in the "no-man's-land" at all, it could be said that this trench is constructed as a barrier against the military vehicles.
(This picture is a montage)