A century-old history of Tianjin, a thousand-year history of Beijing - summer, the third day of Tianjin on the 12th, Tianjin on the third day of Tianjin - the road with the photograph 4 Tianjin geological structure is complex, most of them are covered by Cenozoic sediments. The terrain is mainly plains and depressions, there are low hills in the north, and the altitude gradually declines from north to south. The highest in the north, 1052 meters above sea level; the lowest in the southeast,3.5 meters above sea level. The highest peak in the city: Jiushan Mountain (1078.5 meters above sea level). The total outline of the landform is high in the northwest and low in the southeast. Tianjin has three kinds of terrain, mountainous, hilly and plain, the plain accounts for about 93%. Except for the northern border with Yanshan Mountain, which is mostly mountainous, the rest are alluvial plains, and the northern mountainous areas of Jixian County are low hills below kilometers above sea level. Close to the mountain is a fan-shaped tilting plain composed of flood alluvial fans. The tilting plain is alluvial plain to the south and the coastal plain to the southeast.