Mutianyu's 2.5 kilometer stretch of the Wall allows visitors to walk for more than an hour as they explore 22 watchtowers and the valley on both sides of the Wall.

Watch tower is a tower built on the ramparts to defend the city against the enemy, which is used for the troops in each section to conduct observation, pass orders and place instruments and materials. It can serve as a resting place for the defending officers and soldiers, and is a facility to reinforce the defense of the city wall.The fortress is chosen to be built on favorable terrain for defense, so as to achieve the effect of defeating more with less.