The Northern Beiwei Dynasty made Datong its capital from 398-494 AD, Datong has served as the political, economic and cultural center of the Northern China and was then the one of the largest cities in the world. It was also the alternate capital of Liao & Jin Dynasties known as the West Capital. In Ming & Qing Dynasties, it became a prefecture, one of the nine important strongholds along the Great Wall, that has given Datong a rich historical and cultural heritage: including the Yungang Grottoes, a world cultural heritage, the Upper & Lower Huayan Temple, the Shanhua Temple and the Nine Dragon Screen.