WORLD HISTORY

Detailed explanation-1: -Most of the familiar images of the wall show Ming-era construction in the stone. Depending on how the wall is measured, it stretches somewhere between 4, 000 and 5, 500 kilometers (2, 500 and 3, 400 miles).

Detailed explanation-2: -The Great Wall of China is the longest wall in the world. Its construction began during the reign of the first Chinese Emperor Shi Huangdi of the Qin dynasty in order to protect China from barbarian tribe attacks. The wall is almost 2400 km long and varies in height-from 4.5 m to 9 m.