Guangzhou, known historically as Canton or, less commonly as Kwangchow, is the capital and largest city of Guangdong province, People’s Republic of China. Located on the Pearl River, about 120 km (75 mi) north-northwest of Hong Kong and north-northeast of Macau, Guangzhou is a key national transportation hub and trading port. One of the five National Central Cities, it holds sub-provincial administrative status. Guangzhou is the third largest Chinese city and southern China’s largest city. As of the 2010 census, the city had a population of 12.78 million.