Guangzhou is the capital and largest city of the Guangdong province in the People's Republic of China. Located in southern China on the Pearl River, about 120 km north-northwest of Hong Kong, 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 city in China and southern China's largest city. As of the 2010 census, the city had a population of 12.78 million. Some estimates place the population of the entire Pearl River Delta Mega City built up area as high as 40 million including Shenzhen (10.36 million), Dongguan (8.22 million) and most parts of Foshan (7.19 million), Jiangmen (4.45 million), Zhongshan (3.12 million) and a small part of Huizhou adjoining Dongguan and Shenzhen, with an area of about 20,000 square kilometres (about the size of US state of New Jersey).