The Pearl River Delta Economic Zone (once called 粤江平原), is in the Pearl River Delta region, the expansive delta lands of the Pearl River at the South China Sea. It consists of Guangzhou, Shenzhen, Dongguan, Foshan, Zhongshan, Zhuhai, Jiangmen, and parts of Huizhou and Zhaoqing, has been the most economically dynamic region of the Chinese Mainland since the launch of China's reform programme in 1979. Adjacent Hong Kong is not part of the economic zone.