The watchtowers also provided a place to retreat to, if necessary, from attackers who had scaled the Great Wall. Inside, the watchtowers have narrow and puzzling layouts to confuse any infiltrators. The internal passageways and staircases were unique and restricted. This allowed defenders to pick off attackers one by one.

Barracks and administrative centers were located at larger intervals along the Great Wall. Small armies were garrisoned along the length of the wall to provide early warning of invasion and a first line of defense.

The outer parapet of the Great Wall is crenelated with merlons almost 2 m high from the base of the wall. The merlons provided protection from incoming fire while the gaps allowed fire at invaders.

Source: beijingguide2008.com

Editor: Feng Hui