The famous wall built to protect China from invasions is the Great Wall of China. Construction of the wall began as early as the 7th century BCE and continued for centuries, primarily during the Ming Dynasty (1368-1644). The Great Wall stretches over 13,000 miles, serving as a defense against invasions from nomadic tribes in the north. It also facilitated trade along the Silk Road and helped consolidate the power of the Chinese empires. Today, the Great Wall is a UNESCO World Heritage Site and a significant cultural symbol, attracting millions of visitors from around the world each year.