With its vast torrent, haughty and imposing, yet spontaneously refreshing, the Iguazu River offers its thousands of visitors the fascinating picture of a conglomeration of obstacles, islets and elongated islands, breaking it up into innumerable branches.

The Guarani people called it Iguazu, literally "great water", as they gazed in amazement and rapture at the immense sheet of water diving in a majestic torrent from the heights at various points along its course.

Nowadays those feelings of wonderment are repeated constantly, in the hearts of each of those who live here, and in every fiber of visitors.

The source of the river is in the Sierras Do Mar, just a few kilometers from the Atlantic Ocean, at a height of 900 meters above sea level. Its earliest springs are formed near the city of Curitiba, capital of the Brazilian State of Parana, where it is known as the Rio Grande de Curitiba.

The river forms a natural border between the Argentine province of Misiones and Brazil. Its approximate length is 1,300 kilometers, of which 1,205 are in Brazil, and 115 make up part of the Argentine-Brazilian border; the Argentine part begins exactly where it is joined by its tributary, the Rio San Antonio, and ends when it flows out into the River Parana, 23 kilometers below the Falls.

The waters of the Iguazu and the Parana do not mix immediately, and for a long time those of the Iguazu can be easily differentiated by their light, transparent and greenish hue as they whirl around the darker, reddish waters of the Parana, until they are finally absorbed by the latter.

At the confluence of the two rivers, the borders of Argentina, Brazil and Paraguay can all be clearly distinguished.

As it runs through Brazilian territory it forms numerous falls that are very picturesque but not as large as the Iguazu Falls: the Cayacanga, 10 meters in height; the Do Funil Falls, some 12 meters high; the Passo Falls; the very tall and beautiful Santiago Falls; the Osorio; the Caxias and the Faraday falls.