Watch towers were built at regular intervals on the Great Wall itself for watching over the invading enemy. Some of the watch towers were built on sheer cliffs and irregular mountain projections of strategic importance, and some of the watch towers were built with a small house in the middle, a wooden roof and all around there were holes for shooting arrows.
A watch tower was usually two stories high, and the defense s soldiers lived inside. The ground floor was used for storing weapons and had a number of Windows for archers. The upper floor had battlements, peep holes and apertures for archers. In the middle of the tower there were small living quarters for the defense soldiers. On the upper part, shooting holes were built along the battlements on the Wall for shooting arrows. The watch towers were n not only used by the defending troops to take shelter from the wind, rain and heat, but also to fight and check the enemy’s advance, and store arms and ammunition. So the whole Great Wall formed a complete defensive project with great strategic significance.