Introduction to Waimingtang: The ancient Chinese Feng Shui theory believes that water has a boundary to prevent the loss of dragon energy. Guo Pu, a Feng Shui theorist of the Jin Dynasty, believed that dragon energy "disperses when encountering wind and stops when bounded by water", so it is set up in the mausoleum area Mingtang plays the role of gathering spiritual energy and preventing the loss of dragon energy, which means that the emperor's career will always be prosperous.