Taiwan is an island in East Asia; it is located some 180 kilometres (112 miles) off the southeastern coast of China across the Taiwan Strait. It has an area of 35,883 km2 (13,855 sq. mi) and spans the Tropic of Cancer. The East China Sea lies to the north, the Philippine Sea to the east, the Luzon Strait directly to the south and the South China Sea to the southwest. Taiwan Island makes up 99% of the territory of the Republic of China (ROC), after the ROC lost its mainland China territory in the Chinese Civil War and fled to the island in 1949, and the country itself is commonly referred to as simply "Taiwan".