The Great WallThe Great Wall of China is an ancient Chinese wall built since c. 220 B.C, when under Qin Shi Huang, fortifications were joined together to protect the Chinese Empire and to built a system of defense against intrusions by nomadic groups from the north. This military structure continued growing up to the Ming dynasty (1368–1644), when it became the largest military structure in the world.
The Great Wall begins in the east at Shanhaiguan, in Hebei province, and ends at Jiayuguan in Gansu province to the west. The structure is composed by walls, horse tracks, watch towers, shelters and fortresses along the whole wall. There were required millions of workers to built the wall, and approximately 10 millions died during the construction and were buried there. Therefore, The Great Wall is believed to be the biggest human cementery in the world. In addition, during the peak of the Ming, it was guarded by one million soldiers.
Including all of its divisions and secondary structures, The Great Wall is thought to had measured approximately 8851 kilometers long, but nowadays only the 30% is conserved. On average it has a height between 6 and 7 meters and a width between 4 and 5.
Throughout its history, it has been continuously under construction and reconstruction to protect the 20, 000 kilometers of the Chinese Empire and it shows the impressive political strategic thinking of the ancient China, its powerful military archictecture, technology and art.
About its architecture, there were used materials that could be obtained in the wall´s sorroundings. Limestone was used, for example, near Pekín, but te most common materials were clay, granite and bricks, making an appropriate structure to resist invasions.
It has also a lot of notable areas as the three main doors, but The Great Wall´s most peculiar section is that one that climbs extremely steep hills and slopes. This section is 11 kilometers long and it is composed by 67 watchtowers, 980 meters above sea level.
The location of the watchtowers, barracks and quarters was selected according to the strategic importance that the area offered. For this reason they are located in strategic points as for example peaks of hills.
-Great Wall of China (2013). In Wikipedia, the Free Encyclopedia. Retrieved 17:51, December 17, 2013, from http://en.wikipedia.org/wiki/Great_Wall_of_China
-The Great Wall. In UNESCO. Retrieved 17:53, December 17, 2013, from http://whc.unesco.org/en/list/438/