Iguaçu Falls are waterfalls of the Iguazu River on the border of Brazilian State Paraná and Argentine Province Misiones. The falls divide the river into the upper and lower Iguaçu. The Iguazu River originates near the city of Curitiba. It flows through Brazil for most of its course. Below its confluence with the San Antonio River, the Iguaçu River forms the boundary between Brazil and Argentina.