Introduction to the source of the Luan River: The boundary river is the boundary river between Hebei Province and the Inner Mongolia Autonomous Region. The name of this river is "Tuligan River", which is Mongolian and means crooked and narrow. The river is winding and winding, the water is gurgling and crystal clear, like a silver jade belt, falling in the forest and grassland outside the Great Wall. Ms. Qian Zhengying, Minister of Water Resources, once visited here for inspection and determined that this is one of the main rivers where the Luan River originates, so it is named "the source of the Luan River".