Island (pop., 2000: 3,643,016), westernmost of the Visayan group, central Philippines. It is surrounded by the Sibuyan, Visayan, and Sulu seas, and the Guimaras Strait separates it from Negros island. Roughly triangular in shape, it has an area of 4,446 sq mi (11,515 sq km). A rugged, almost unpopulated mountain range parallels its western coastline. Between the range and a hilly eastern portion, a densely populated, intensely farmed fertile plain extends north to south. The island's chief city is Iloilo.