Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Iguazu River is a river in Brazil and Argentina. It is an important tributary of the Paran River. The Iguazu River is 1,320 kilometres (820 mi) long, with a drainage basin of 62,000 square kilometres (24,000 sq mi). The Iguazu originates in the Serra do Mar coastal mountains of the Brazilian state of Paran . For 1,205 kilometres (749 mi), to its confluence with the San Antonio River, the Iguazu flows west through Paran State, Brazil. Downriver from the confluence the Iguazu River forms the boundary between Brazil and Argentina's Misiones Province.