The Biobío River (also known as Bío Bío or Bio-Bio) is the second largest river in Chile. It originates at Icalma and Galletué lakes in the Andes and flows 380 kilometres (236 mi) to the Gulf of Arauco (in Spanish) on the Pacific Ocean.
The major tributaries of the river are the Malleco and the Laja. The river is Chile's second-longest river (the longest being the Loa River) and the Biobío basin is Chile's third largest watershed, after the Loa and Baker basins. The river is also the widest river in Chile, with an average width of 1 kilometre (0.6 mi). In the Metropolitan area of Concepción, four bridges cross the river: Biobío Railroad Bridge (1889), Juan Pablo II Bridge (1973), Llacolén Bridge (2000) and Bicentennial Bridge (2010).