With the threat of the Martian invaders growing, the Americans began a massive program of fortification construction. Concrete proved the idea material to provide protection from the enemy's dreaded heat rays. High walls, too tall for the Martian tripods to cross, began to ring American cities. This kit includes eight 5 1/2" long wall sections. The walls are 4 1/4" high with a walkway for troops which is 3 1/2" high. The wall sections are 2" thick. There are also two printed gates which can be applied to the wall sections.