On the east coast of Eurasia and the southern tip of Liaodong peninsular in northeast China, Dalian stretches from 120°58' to 123°31' east longitude and 38°43' to 40°10' north latitude, with the Yellow Sea on the east, Bohai Sea on the west, facing the Shandong peninsular across the sea on the south and backed up by the vast Northeast Plain on the north. Dalian is the marine gateway of northeast China, North China, East China and the whole world. It is also an important port, and a trade, industry and tourism city. Dalian covers an area of 12574 square kilometers, among which 2415 square kilometers of area is the old city. This area abounds with mountains and hills, while plains and lowlands are rarely seen. The terrain, high and broad on the north, low and narrow on the south, tilts to the Yellow Sea on the southeast and the Bohai Sea on the northwest from the center. The region which faces the Yellow Sea is long and gentle. The Qianshan Mountain range of Chang Baishan Mountain system passes through the whole region from north to south. Mountain regions and long eroded foothills are widely dispersed within the region. Plains and lowlands are only interspersed near the confluence and in some valleys. Kast topography and sea erosion topography are everywhere.