The Great Wall is mainly made of a continuous castellated wall walk, of approximately five meters wide. Its laying out and the building materials used adjust to the relief met. Thus, depending on the age and the position of the Great Wall, it can be made of rammed earth, stone or bricks, (and even of reed and palm leaf in the Golbi Desert). It is seven to eight meters high and five to six meters wide. The platform is wide enough to allow five horsemen abreast. Stairs were regularly distributed along the Great Wall, close to the defence towers when there were no ramps. They were protected by an arched tunnel, driven in the thickness of the Great Wall. The water draining wasn’t left at random: gargoyles hewed in the large stones ejected the water outside. The falling water landed on stones on the ground which prevented it from penetrating into the foundations. To protect the guards patrolling on the portions with towers, the Chinese built wooden shelters called Pu Fang.  + photos ...