Introduction to the ruins of the ancient Great Wall: Only the rammed loess foundation remains on the Shahukou Pass and the ruins of the ancient Changcheng Castle. There is an ancient road paved with large and small stones along the pass to the south, and its ruts are clearly identifiable. There are many Manchus in the surrounding villages, and it is said that they are all descendants of the Eight Banners Army who stationed at Shahukou.