Haikou, situated at the north of Hainan island, is the capital of Hainan Province of the People's Republic of China and has an estimated population of 631,179 (2006), therefore by far the largest city on the island. Location: located in an area that reaches from Zengmu Ansha in the south to the Qiongzhou Strait in the north; bordering the sea areas of the South China Sea and facing Vietnam in the west across Beibu Bay.