The Great Wall of China, also known as the Ten-thousand-Li Great Wall, is a remarkable feat of engineering and a symbol of Chinese history. Stretching over 6,000 kilometers from west to east, it meanders across deserts, mountains, and valleys, finally reaching the sea. This monumental structure has a history of over two millennia, with the first sections constructed during the Spring and Autumn Period and additional walls built during the Warring States Period to defend the various kingdoms' borders. It was during the Qin Dynasty that the kingdom of Qin united these sections into one empire, with the primary aim of protecting China's northern frontier