The Great Wall of China
The great wall of China is an extensive bulwark erected in ancient. It is one of the largest building construction projects ever carried out in this world. It runs with all its branches, about 4,500 miles east to west from Shan hai pass near Po Hai (Gulf of Chihli) to Chia-yu Pass (in modern Kansu province). Without its branches and other secondary sections, the wall is about 4,160 miles long. The wall often runs along the crest lines of hills and mountains as it snakes across the Chinese countryside. Large parts of the were built from the 7th through the 4th century BC. In the 3rd century BC Shih Huang-ti, the first emperor of a United China, joined some existing defensive walls into a single system. Although lengthy Sections of the wall are now in ruins or have disappeared completely, it is still one of the most remarkable structures on earth. The great wall was added to the UNESCO World Heritage List in 1987.