What is some great info about the great wall of china?
Communication between the army units along the length of the Great Wall, including the ability to call reinforcements and warn garrisons of enemy movements, was of high importance. Signal towers were built upon hill tops or other high points along the wall for their visibility. The Great Wall is a maximum 9.1m (30 ft) wide and is about the same color as the soil surrounding it. The Great Wall winds up and down across deserts, grasslands, mountains and plateaus, stretching approximately 6,700 kilometers (4,163 miles ) from east to west of China. The Great Wall was originally built in the Spring, Autumn, and Warring States Periods as a defensive fortification by the three states: Yan, Zhao and Qin. The Great Wall of China was built as a key to protect the agricultural lands from invasion and to keep the nation’s people from vacating the empire. The sections in the eastern part of China were built out of bricks and stones while in the western sections of wall were made out of less durable
