TETRAHEDRON

SN Triangular concrete pyramids with 6 feet long sides and 5 feet high, intended to impede enemy movement in the event of invasion. Thought to be confined geogaphically to Southern Command.
CL MILITARY DEFENCE AND FORTIFICATION
BT ANTI TANK BLOCK

 
 

TETRAHEDRON

SN Triangular concrete pyramids with 6 feet long sides and 5 feet high, intended to impede enemy movement in the event of invasion. Thought to be confined geogaphically to Southern Command.
CL MILITARY DEFENCE AND FORTIFICATION
BT ANTI TANK BLOCK