Orinoco, << `ohr` uh NOH koh, >> River is the longest river in Venezuela. It is 1,284 miles (2,066 kilometers) long. The Orinoco has two known sources, both in the Parima highlands in Venezuela, near the border of Brazil. The river flows northwest to Colombia and forms the boundary between Colombia and Venezuela. Then it swings east across Venezuela. About 110 miles (177 kilometers) before it reaches the seacoast, it divides into many channels. Major branches of the Orinoco are the Apure, Caroni, and Meta rivers.