The Great Wall of China is one of the most iconic landmarks in the world. Built to protect Chinese states and empires from invasions, the wall stretches over 13,000 miles. Construction began in the 7th century BC and continued for centuries, involving millions of workers. Many sections of the wall were made from locally available materials, such as stone, brick, and tamped earth. Over time, the Great Wall has faced natural erosion and human activity that threaten its preservation. Today, it is a UNESCO World Heritage Site and a symbol of China's historical resilience, attracting millions of tourists annually and sparking global interest in its history and cultural significance.