How long did it take to build the Great Wall of China?
I came up with a different answer: The Great Wall of China was built over more than two thousand years. Construction on the first section began between the 7th and 6th century BC, and the last work on the wall was done between the 14th and 17th centuries. After subjugating and uniting China from seven Warring States, the emperor connected and extended four old fortification walls along the north of China that originated about 700 B.C. (over 2500 years ago). The Great Wall of China is not a continuous wall but is a collection of short walls that often follow the crest of hills on the southern edge of the Mongolian plain. Overall, the wall extends about 1500 miles (2400 kilometers). A first set of walls, designed to keep Mongol nomads out of China, were built of earth and stones in wood frames during the Qin Dynasty (221-206 BCE).
