The Great Wall of China is famous because it is an architectural feat of ancient China that is also the longest man-made wall in the world. The main purpose for building this structure was as a defensive fortification against invaders.
The construction of the Great Wall of China began in the third century B.C. Soldiers, commoners and convicts worked on this building project. It is believed that approximately 400,000 people died during its construction. This construction project was completed in the 16th century. In the 17th century, the Manchus were able to break through this fortification.
In 1987, the Great Wall of China was designated as a World Heritage site by UNESCO. Although its official length was given as 5,500 miles in the past, a recent archaeological survey estimates that the entire length of the Great Wall was 13,170 miles during the 2,000 years of its construction.