The Great Wall is the longest wall in the world. Mongolian called Kmแpgkaw Chinese called Mansion walls. The walls of the fort, Jia Yu Guan. The foothills Qi Lian San As arid west. Cutting through the desertRiver valleys and forests abutting the Yalu River to the east, which borders on Korea. Wall across northern China, and the length to 3,.200 The total, the building is separated from the wall of the well. It has a length of 6,500 kilometers.