The Great Wall of China is a massive fortification structure that stretches over 13,000 miles (21,196 km) in northern China. It was originally built in sections during various Chinese dynasties, starting in the 7th century BC, and was later connected and strengthened during the Ming Dynasty (1368-1644) to protect China from invading Mongolian and Manchurian armies.

The Great Wall consists of several sections, including the most popular ones like Badaling, Mutianyu, Jinshanling, and Simatai. These sections have been restored and are open to tourists, with some offering cable cars, toboggan rides, and hiking trails.

The Great Wall is a UNESCO World Heritage Site and one of the most famous landmarks in the world. It is a symbol of China's ancient civilization and military might, and a testament to human engineering and construction capabilities. The wall is also known for its stunning views, especially during sunrise or sunset, making it a popular destination for photographers and travelers from around the world.