Chengdu is located in the middle of Sichuan Province in the west part of the Sichuan basin, between 102°54´ and 104°53´ east latitude and between 30°05´ and 31°26´ north longitude. It is the center of science and technology, trade and commerce and finance and the hub of transportation and telecommunications in the southwest. It is adjacent to Deyang city in the northeast, Neijiang city in the southeast, Leshan city in the south, Ya'an prefecture in the southwest, and Aba Tibetan autonomous prefecture in the northwest. The average height of the Chengdu plain is 500 meters, with the highest point reaching 5,364 meters above sea level and the lowest point 387 meters. Its geographical features mainly involve plains, plus hills and mountains, with the terrain slanting from northwest to southeast. In the northwest is the Qionglai Mountain, and in the northeast is the Longquan Mountain. The city covers a total area of 12,390 square km including 87 square km of urban area, with a total length of 192km from east to west and 166km from north to south.