The Great Wall of China holds significant historical importance as a symbol of Chinese strength, engineering prowess, and perseverance. Initially constructed between the 7th and 4th centuries BCE and later expanded by the Ming Dynasty, the wall was built primarily to protect Chinese states and empires from invasions and raids by nomadic groups from the north. Beyond its military purpose, the Great Wall served as a barrier to control immigration and emigration, facilitate trade along the Silk Road, and symbolize national unity. It is a UNESCO World Heritage site and attracts millions of visitors each year.