The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Philippines (mainly Luzon, Mindoro and Palawan), and in the south by Borneo, eastern Sumatra and the Bangka Belitung Islands, encompassing an area of around 3,500,000 km2 (1,400,000 sq mi). It communicates with the East China Sea via the Taiwan Strait, the Philippine Sea via the Luzon Strait, the Sulu Sea via the straits around Palawan (e.g. the Mindoro and Balabac Strait), the Strait of Malacca via the Strait of Singapore, and the Java Sea via the Karimata and Bangka Strait. The Gulf of Thailand and the Gulf of Tonkin are also part of the South China Sea. The shallow waters south of the Riau Islands are also known as the Natuna Sea.