In geomantic metaphysics, we divide the twenty-four mountains into three dragons: earth, heaven and man. Seventy-two dragons, that is, sixty dragons in sixty jiazi plus twelve empty dragons in the middle of eight thousand four dimensions, are called seventy-two dragons. Some modern geographers are called Chuanshan Tiger, and some are called Qiliangmao. It was created by Yang Junsong in the Tang Dynasty, who found that the acupuncture method of Yin-Yang Dragon was too rough and the accuracy of taking advantage of the situation was too poor.