TunnelsThe first characteristic of a tunnel complex is normally superb camouflage. Entrances and exits are concealed, bunkers are camouflaged and even inside the tunnel itself, side tunnels are concealed, hidden trapdoors, and dead-ends where used to confuse the attacker. Trapdoors were used extensively, both at entrances and exits and inside the tunnel complex itself. There where several different types of trapdoors, concrete covered by dirt, hard packed dirt reinforced by wire, or a basin type consisting of a frame filled with dirt. This latter type was particularly difficult to locate in that probing would not reveal the presence of the trapdoor unless the outer frame was actually struck by the probe. Trapdoors covering entrances were generally 100 meters apart. Booby traps were used both inside and outside entrance and exit trapdoors. Tunnels found in the War Zones were generally better constructed than those found in other areas. In some cases these complexes were multileveled, with storage and hiding rooms generally found on the lower levels.
