Guangzhou is located in southern China in the middle of Guangdong province, north of the Pearl River Delta. The city also lies close to the South China Sea, Hong Kong, and Macao. Because of its convenient geographical position, Guangzhou has been called 'China's Southern Gateway'. As the capital of Guangdong province, Guangzhou is the center of its politics, economy, science, education. It is also southern China's key transportation hub and trading port.