The Great Wall of China is the biggest object ever made by humans. It stretches across mountains, deserts and grasslands for over 6,000 kilometres. The ancient Chinese built the wall to keep invaders from the west out of their country. Today tourists from all over the world come and see it.
The Great Wall began as a series of many smaller walls that were not connected with each other. The first sections of the wall were built as early as 600 B.C. As time went on Chinese emperors connected them together to keep Huns, Mongols and other tribes out. Thousands of soldiers, criminals and peasants worked on building the wall. It was finally completed during the Ming dynasty in the 17th century.
The Chinese wall is made of dirt, mud, stone and brick. It is between 5 and 9 metres tall and up to 8 metres wide. A small road runs on the top of the wall. Towers every few hundred metres were built to store military supplies. They served as watch posts and were used to send information. Guards fired cannonballs or used smoke signals to inform other towers of possible invaders. At times up to a million Chinese soldiers guarded the wall. Towards the end of the Middle Ages the great wall lost its military function.
Over the centuries parts of the wall have been damaged by weather, earthquakes and war. The government destroyed some parts of the wall to build new roads or for other construction projects. In the western part of China sandstorms have covered part of the wall. As a result almost half of the wall has disappeared completely, while about 30% is in fairly good condition.
In 2006, the Chinese government started taking action to protect the Great Wall. Today the wall is a World Heritage Site, a symbol of China and a big tourist attraction. The most visited section is a part near Beijing which 6 million tourists go to every year.