The significance of the Great Wall of China lies primarily in its role as a defensive structure. Built over centuries, it was designed to protect Chinese states from invasions by nomadic tribes, primarily from the north. The wall served not only as a physical barrier but also as a psychological deterrent to potential attackers. It encompassed watchtowers and garrisons, allowing for surveillance and communication. Beyond defense, the Great Wall also facilitated trade and cultural exchange, symbolizing the strength and ingenuity of Chinese civilization throughout history, making it an enduring national symbol.