Sand storms have been at the forefront of causing damage to the great wall. But this by no means is the only factor resulting in the erosion of the Great Wall. The change in climate that has taken place over the years has also had a profound effect on the state of the Great Wall.
Major section of the wall built during Qin Dynasty is ruined and destroyed completely. The Great Wall of China that you see today is mainly built by the Han, Sui, and Liao dynasties that ruled China in later years. During their era they repaired various sections of Great Wall.
The forts along the wall were used as housing, as storage facilities and as towers to give a better view. They varied considerably in size all the way up to Castle size.
The Great Wall of China owes its existence to the history of the interaction between the settled agricultural communities of China and their predominantly nomadic neighbors to the north.
Juyongguan is not the site of one of the most frequently visited stretches of the present Great Wall of China, but in 1211 there was nothing to stop the Mongol advance except some minor fortifications.
To guard against the northern nomadic tribes, Chu State of the Warring States Period (476 - 221BC) built the earliest wall named 'Fangcheng', followed by Qi, Yan, Wei, Zhao, and Qin states. Later, Emperor Qinshishuang had the walls of the vassal states connected after his unification of China
Measuring about 8,851.8 km (5,500 miles) long, the Great Wall is no doubt the longest manmade project on the earth. It was once widely believed that it can be seen from the space. Many astronauts have verified this saying and taken photos as evidence.
Many people who worked to build the Great Wall had no choice. They often were soldiers who were ordered to build the wall and prisoners who had been sentenced to hard labor. Common people also worked on the wall. The working conditions were so dangerous that many workers lost their lives during the construction, and it is said that many of them remain buried in the wall.
In the last century, due to various environmental reasons and human activities, about one million square kilometers (400, 000 sq miles) of land from Xinjiang to the Songneng Plains are changing from arable land into desert. This trend has led to rapid erosion and burial of the Great Wall. Also, large parts of the ancient wall, beacon towers and watchtowers have been damaged or dismantled by the uncontrolled activities of local people and developers.
The Great Wall of China, along with Terracotta Army and Tian’an Square, is a symbol of the People’s Republic of China.
The Great Wall of China was initially built over two thousand years ago by Qin Shihuang, who summoned one twentieth of the country’s population to join the project of building.