The Great Wall winds up and down across deserts, grasslands and  mountains stretching approximately 8,851.8 kilometers (5,500 miles) from east to west of China. It a series of stone and earthen fortifications built between the 5th century BC and the 16th century to protect the northern borders of the Chinese Empire  during the rule of successive dynasties. Some of the sections are now in ruins or have disappeared. However, it is  one of the greatest sights in the world.