The Great Wall of China，one of the greatest wonders of the world，was enlisted in the World Heritage by the UNESCO in 1987.Just like a gigantic dragon，the Great Wall winds up and down across deserts，grasslands and mountains，stretching about 6,700 kilometers from east to west of China.With a history of more than 2,000 years，some parts of the Great Wall are now in ruins or even entirely disappeared.However，it is still one of the most appealing attractions around the world.

　　No one can tell for sure when the building of the Great Wall was started，but it is popularly believed that it originated as a military fortification against intrusion by tribes on the borders during the earlier Zhou Dynasty.Late in the Spring and Autumn Period，some states extended the defence work to prevent the attacks from other states.

　　It was not until the Qin Dynasty that the separate walls were connected to form a defensive system by Emperor Qin Shi Huang.After the emperor unified the country in 214 BC，he ordered the construction of the wall.It took about ten years to finish and the wall stretched from Gansu Province to Jilin Province.The wall not only served as a defence in the north but also symbolized the power of the emperor.

　　Further construction also experienced several dynasties.The present Great Wall in Beijing is mainly from the Ming Dynasty.Today，the Great Wall has become a must­see for every visitor to China.Few can help saying "Wow" when they stand on top of a beacon tower and look at this giant dragon.It has become a national pride of Chinese people.

1.enlist vt.列入

2.gigantic adj.巨大的

3.stretch v.伸展

4.fortification n.筑垒；防御工事

5.intrusion n.侵袭，侵扰

6.tribe n.部落

7.beacon tower烽火台