Lanzhou is the capital of Gansu Province and also the second largest city in the northwest area of China. The city covers a total area of 13,000 square kilometers with a population of 2.58 million. The city's land features include valleys, basins, hills, and gully areas. Lanzhou also served as an important garrison along the Silk Road. Lanzhou has a temperate climate and elevation around 1000-2000 meters above the sea level. The Yellow River is flowing through the whole city. Most parts of the area are semi-dry climate in the temperate zone. Amongst the splendid sites in and around the city, the most famous is the Bingling Temple Caves. Other places of interest are Wuquan Mountain, Baita Mountain and Xinglong Mountain, all summer resorts, and Lutusi ancient government, the most complete ancient palace building that has survived through China's long history. Lanzhou's primary resources are coal, gold, silver, zinc, manganese, clay, dolomite, etc. The major industries are oil refinery, chemical, machinery and metallurgical industry. Moreover, Lanzhou is an important center for rose-oil, which accounts for 80% of China's total output.