The Iguazu River (Portuguese: Rio Iguaçu[2] [ˈʁi.u iɡwaˈsu], Spanish: Río Iguazú [ˈri.o iɣwaˈsu];[3] also called Rio Iguassu[4]) is a river in Brazil and Argentina. It is an important tributary of the Paraná River. The Iguazu River is 1,320 kilometres (820 mi) long, with a drainage basin of 62,000 square kilometres (24,000 sq mi).[5]