Castle introduction: The castle in Niangziguan is backed by the high Mian Mountains reaching the sky, facing a deep valley with cut walls. The battlements on the mountainside meander along with the mountains, and the Tao River surrounds it to the northwest. , twists and turns, it is really "a mountain with water, a golden city soup pool". The two wings of the entire Guancheng are the Great Wall that meanders along the mountains. The Great Wall here has historically become a natural barrier between Shanxi and Hebei provinces. It is true that "one man The momentum of "If the barrier is closed, no one can open it" is very dangerous.