Chongqing (; Postal map spelling: Chungching, also Chungking) is the largest and most populous of the People's Republic of China's four provincial-level municipalities, and the only one in the less densely populated western half of China. Formerly (until March 14, 1997) a provincial city within Sichuan Province, the municipality of Chongqing has a registered population of 31,442,300 (2005), with most of them living outside the urban area of Chongqing proper, over hundreds of square kilometres of farmland. The population of the urban area of Chongqing proper was 12.057 million in 2005, making it the third most populous city in China.