<human>:  What is the history of the Great Wall of China?
<bot>: The Great Wall of China is an extensive line of fortifications that were constructed by several different Chinese Empires over a period of more than 2,000 years with the earliest construction beginning during the 7th century BCE. It stretches for more than 13,000 miles across Northern China and is visible from space. Its purpose was to protect China from the invading forces of its neighbors and also to regulate the movement of civilians, goods, and ideas in and out of the Empire. The wall was expanded and modified during different dynasties and periods throughout Chinese history, and served as a symbol of the power and control of the ruling regime. It has survived in various forms to become one of the most iconic monuments in the world.