Guangzhou is at the center of the Guangdong–Hong Kong–Macau Greater Bay Area, the most populous built-up metropolitan area in the world, which extends into the neighboring cities of Foshan, Dongguan, Zhongshan, Shenzhen and part of Jiangmen, Huizhou, Zhuhai and Macau, forming the largest urban agglomeration on Earth with approximately 70 million...