Taiwan (historically known as Formosa, from Portuguese: Ilha Formosa, "Beautiful Island", Portuguese pronunciation: [ˌiʎɐ fuɾˈmɔzɐ]) is an island in East Asia; located some 180 kilometres (112 miles) off the southeastern coast of mainland 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 proper makes up 99% of the territory of the Free Area controlled by the Republic of China since the ROC lost its mainland China territory in the Chinese Civil War and fled to the island in 1949; this area itself is commonly referred to as simply "Taiwan".