307 years ago today, on June 19, 1718 (Lunar Calendar 21 May 1718), the Gansu Chongqing 7.5 earthquake. On June 19, 1718 (Congqing 517 May 21st), the Gansu Chongqing 7.5 earthquake formed Zhao's cave slopes and cave slopes, not only the slopes are large, but the injuries are severe. In the consolidation of Qingqing, the "seismic record" is written in detail, describing Zhao's house. The slopes buried the town of Yongqing: "The earthquake is dark, the light is cloudy, the thunderstorms are not stopped, the thunderstorms are overturned ten times."