At the end of the Minjiang River, there is one some small lake with the name of Diehai, it is a barrier lake. At first sight, you may never imagine that this lake had swallowed almost about 6800 people under water. Before 1933, the lake was the vital communication stronghold what links between the west and the east, most of the majors were fight with each other to obtain this city, so it is a frontier defence town, which has an important function. In 1933, one night, the earthquake happened that everybody were fell asleep, suddenly, the sound burst, all the town became one big hole, and because this city backed with hills, heavy raining made the condition worse, water put into tje hole, hills and muds rushed in to the hole, and all the town buried underground. After a few years, the lake surface become peaceful even more and more beautiful, i really dont want to use the "beautiful" to describe it.But this lake now really has important value for science research.