Guangdong province is located in the southernmost part of the Chinese mainland. It adjoins Fujian province in the east and Jiangxi and Hunan provinces in the north. To the west, it is Guangxi Zhuang autonomous region, and to the south the South China Sea. China's second-largest river - the Pearl River - flows through Guangdong. To the east of the Pearl River Estuary, it is the Hong Kong Special Administrative Region and to the west, Macao Special Administrative Region. The southwestern Leizhou Island in Guangdong is separated from Hainan province by the Qiongzhou Strait.