The Iguasu Falls are situated in the middle of the National Park, Parque Nacional Foz do Iguasu Falls, which is divided between Brazil and Argentina. The Brazilian National Park was founded in 1939 and the area was designated a World Heritage Site by UNESCO in 1986.
Iguasu Falls are considered to be one of the seven wonders of the modern world. The Iguasu Falls river basin extends over some 62,000 km2.
The Rio Iguasu Falls rises in the Brazilian hills near Curitiba at an altitude of around 1,200 m, from where it flows west for some 1,300 km across the Parana Plateau, a thick layer of very hard basalt lava formed as a result of a massive Triassic volcanic eruption over 100 million years ago. On its way it widens majestically, as a result of receiving the waters of about 30 rivers, and sweeps around a magnificent jungle stage, plunging and crashing in tiered falls, which lie at an altitude of 160 m at the edge of the plateau on the border with Argentina and Paraguay. The falls are over 3 km wide and 80 m high and their beauty is unbelievable.
At the heart of this immense body of water is the Devil's Throat, where 14 separate falls join forces, pounding down the 90 m cliffs in a deafening crescendo of sound and spray. A catwalk runs to the base of the first level of the falls where you are surrounded by the roaring water, the mist and white foam that are boiling up all around, the green of the jungle, uprooted trees and a 180-degree rainbow. It is an overwhelming sensation.
Close to the falls, 12 km to the north, is the Itaipa dam, the world's largest power station. It was built jointly by Brazil and Paraguay. It came into operation in 1984 and produces enough electricity to power the whole of southern Brazil and much of Rio de Janeiro, Sao Paulo and Minas Gerais.
Although geology research proves that the Iguasu Falls were formed over 100 million years ago due to massive volcanic eruptions, the falls are steeped in myth and legend according to ancient native Indian beliefs of the tribes that lived on the borders of the Iguasu Falls River. One such legend among the Caingangue Indians tells of the creation of the falls as a result of a tragic love story involving the daughter of an Indian chief.
Most of the falls lie in Argentina, but the Brazilian side offers a more superb panoramic view of the whole falls and is best visited in the morning when the light is better for photography. The Argentine side offers closer views of the individual falls.
The National Park covers 170,086 hectares, extending along the north bank of the Rio Iguasu Falls, and then sweeping northwards to Santa Tereza do Oeste. It contains the world's largest pluvial forest and it benefits from the added humidity in the proximity of the falls, creating an environment rich in flora and fauna. It is home to 12 species of amphibians, 18 species of fish, 40 species of mammals, including the jaguar, ocelot, capybara and giant river otter, 60 different reptiles, 340 bird species, and 700 unique species of butterflies.
The best time of the year to visit is August-November, when there is the least risk of flood waters hindering the approach to the catwalks.