Introduction to Wuguitou Mountain Cave: Wuguitou, formerly known as Luancai Gou, is one of the seven passes of Guangou, located at the foot of Wugui Mountain. Wuguitou Mountain Cave was originally a tunnel of the old Beijing-Zhangjiakou Railway. Now the roadbed has been demolished and abandoned. The cave is 7 meters high, 4 meters wide and 30 meters long.