The Great Wall of China was built by Emperor Shi Huangdi. It is one of the most impressive of *** architectural accomplishments. It is about 2,400 km. long and varies in height from 4.5m to 9m. This wall forms the northern boundary of China. It was built across mountains, deserts and plains. There are 10,000 watch-towers at regular intervals along the wall. It was built to protect the China from the frequent attacks of barbarians.
