The Iguazu Falls are waterfalls of the Iguazu River on the border of the Argentine province of Misiones and the Brazilian state of Parana. They are the largest waterfalls system in the world. The falls divide the river into the upper and lower Iguazu. The Iguazu River rises near the city of Curitiba. For most of its course, the river flows through Brazil; however, most of the falls are on the Argentine side. Below its confluence with the San Antonio River, the Iguazu River forms the boundary between Argentina and Brazil.

The Iguazu Falls are located where the Iguazu River tumbles over the edge of the [Paraná Plateau], 23 kilometres (14 mi) upriver from the Iguazu's confluence with the Paraná River. Numerous islands along the 2.7-kilometre-long (1.7 mi) edge divide the falls into many separate waterfalls and cataracts, varying between 60 to 82 metres (197 to 269 ft) high.

According to wikipedia