The Great Wall, symbolizing China's ancient civilization, is one of the world's most renowned projects. It extends from Shanhaiguan Pass, a seaport along the coast of Bohai Bay, to Jiayuguan Pass in Gansu Province. Its total length is more than 6,700 kilometres.
Construction of the Wall first began during the period of the Warring States (476-221 BC). Formerly, walls were built at strategic points by different kingdoms to protect their northern territories. In 221 BC after the first Emperor of the Qin Dynasty unified China, he decided to have the walls linked up and extended.
Historical records show that about 1 million people, one-fifth of China's population at the time, were involved in the project which took more than ten years. When it was finished we call it “Wan Li Chang Cheng” which means “Ten Thousand-Li-Long Wall”. Now, nature has taken over most of the Great Wall.
Before the Ming Dynasty, the Wall was built mainly of earth and rock. Under the Ming, it was rebuilt in most places with bricks and stones. For instance, the section at Badaling near Beijing was faced with slabs of rock and large bricks and filled with earth and stones. It is 6 to 7 metres high.
The Wall traverses mountains and gullies. It was extremely difficult to build along steep slopes under harsh conditions. Some of the slabs of rock were as long as two metres and weighed as much as one ton. All the rocks, bricks and lime had to be carried up the mountains at the cost of backbreaking labour. The earth and bricks were passed up from hand to hand or carried in baskets by donkeys and goats. The large slabs were moved up slopes by means of rolling rods and hoisting bars. According to rough calculation, the amount of bricks and rock used to build the Wall would have been enough to build a wall five metres high and one metre thick around the world.
The Great Wall of China was named as the top of the New Seven Wonders of the World.