The Great Wall's Secret

The Great Wall of China is an ancient series of fortifications built across the historical northern borders of China to protect against various nomadic groups from the Eurasian Steppe. Its construction began as early as the 7th century BC, with significant additions made during the Ming Dynasty. The wall stretches over 21,196 kilometers (13,171 miles) and is one of the most impressive architectural feats in human history. It served not only as a defensive structure but also for border controls, allowing the imposition of duties on goods transported along the Silk Road, regulation of trade, and the management of immigration and emigration.