A section of the Great Wall of China has been explored for the first time. The ancient wall, which is 405 kilometers long, was nicknamed the "Mongolian Arch" due to its curved shape.
The wall appears to have been built in haste, perhaps due to panic on the part of China's leaders over the invading Mongol armies. The authors of the study cannot currently draw any definitive conclusions about the purpose of the Mongolian Arch. They plan to conduct more extensive excavations of some of the structures in the coming year.