Introduction to the river: About 100 years ago, Stein once again came to Taxkorgan in western Xinjiang, China, with "The Records of the Western Regions of the Tang Dynasty" in mind. He climbed a hill called Kizikurgan and concluded that this was the place where the romantic story took place - the "Princess Castle". He said that Xuanzang's records were correct. This was an ancient castle with an ancient history, and its era could even be traced back to the Han Dynasty, the era when the story took place. He also discovered a large number of ancient settlement relics near Kizkorgan, which proved that this was once the place where the ancient ancestors of Taxkorgan lived. Although Stein's stay at Princess Castle was short, he still drew a very clear topographic map.