Mutianyu is a section of the Great Wall of China located in Huairou District within the city limits of Beijing 70 kilometers northeast of the center of the city. The Mutianyu section of the Great Wall is connected with Jiankou in the west and Lianhuachi in the east. As one of the best-preserved parts of the Great Wall, the Mutianyu section of the Great Wall used to serve as the northern barrier defending the capital and the imperial tombs.