Outside the Sixth Ring Road. Miyun District, located in the northeast of Beijing, is an important drinking water source base and ecological conservation development area in the capital, and also an important gateway for North China to the northeast and Inner Mongolia. The whole territory is 69 kilometers long from east to west and 64 kilometers wide from north to south, with a total area of 2229.45 square kilometers. It belongs to the outer suburbs of Beijing and is located outside the Sixth Ring Road.