The Great Wall of China is one of the most iconic landmarks in the world. Built over several centuries, starting as early as the 7th century BC, it was constructed to protect China’s northern borders from invasions. Stretching over 21,000 kilometers, the wall winds through rugged mountains and plains, showcasing impressive ancient engineering. With its watchtowers and breathtaking scenery, the Great Wall is not only a symbol of China's rich history but also a testament to human determination and ingenuity.