GREAT WALL OF CHINA

One of the most ambitious man made structures on earth the Great Wall of China has a history that dates back to 220 BC when it was made for the protection of the Chinese Empire by Qin Shi Huang the first emperor of China. With estimates placing the entire length of the wall at over 21000km construction continued up till 17th century making it the largest military structure in the world. In 1987 it was designated as World Heritage Site.