What is the postal code of Lanzhou?

According to Baidu Encyclopedia, Lanzhou, formerly known as Lanzhou, Gaocheng and Jincheng, is a prefecture-level city under the jurisdiction of Gansu Province. Its postal code is 730000, its administrative division code is 620 100, its administrative category is prefecture-level city, its telephone area code is 093 1, and its license plate code is Gan A.

Lanzhou is located in the geometric center of the land map of northwest China and Chinese mainland. The terrain is high in the west and low in the south, and low in the northeast. The Yellow River flows from southwest to northeast, and canyons and basins appear alternately. Lanzhou has a temperate continental climate. Lanzhou has a history of more than 2000 years since the Qin Dynasty. Since ancient times, it has been a transportation hub and military fortress of "connecting all directions and taking Wan Li first". Named Jincheng, it means "Jincheng Tang Chi" and is known as the "Pearl of the Yellow River". Due to the Silk Road, Lanzhou has become an important traffic artery and commercial port.