The Great Wall of China loosely comprises of a series of defensive structures put in place across northern China, between the 5th century BC and the 16th century. When Emperor Qin Shihuangdi unified the warring states in 221 B.C. the focus was on centralized rule. Part of his unification campaign included strengthening fortifications on the northern borders. By the Western Han (206 B.C. – 8 A.D.) the Xiongnu (a pastoral-nomadic state) were posing a constant threat to the Chinese from the north-west. Emperor Han Wudi ordered the construction of a wall to secure the Hexi Corridor not only to assert control over the western region but ensure smooth trade links with Central Asia. The Han wall continued on from the terminus of the Qin Wall in Linzhao and traversed the Hexi Corridor for over 300 miles via Jiayuguan to the Yumenguan and Yangguan, both in the Dunhuang area.
At either end of the Dunhuang Great Wall extension stand the remains of two important Han dynasty gates about 42 miles apart. Up until the sixth century, all caravans passing into the city were required to pass through one of these gates and likely pay a tribute to the authorities. The Yumenguan (Jade Gate Pass) to the north acquired its name from the great jade caravans that passed through from Khotan. The Yangguan (Sun Gate), was situated to the south. In today’s Gobi desert just west of the Yumenguan ruins stands one of the oldest remaining sections of the Great Wall, complete with dilapidated beacon towers. These fragmented sections constructed from earth, gravel, reeds and local wood stretch for over a hundred miles. A combination of natural disaster, wind erosion and human intervention has left the wall in poor condition. Many sections have already disintegrated so get here soon!