Upon seeing Iguazu, First Lady Eleanor Roosevelt reportedly exclaimed "Poor Niagara !" Vastly larger than North America's Niagara Falls, Iguazu is rivalled only by Southern Africa's Victoria Falls which separates Zambia and Zimbabwe.

One of the most beautiful water falls in the world, Iguazu waterfalls system consists of about 270 falls along 2.7 kilometres (1.67 miles) of the Iguazu River. Some of the individual falls are up to 82 metres (269 feet) in height, though the majority are about 64 metres (210 feet). The Garganta del Diablo or Devil's Throat, a U-shaped 150-metre-wide and 700-metre-long (490 by 2300 feet) cliff, is the most impressive of all, and marks the border between Argentina and Brazil. Most of the falls are within Argentine territory, but from the Brazilian side a more panoramic view of the Garganta do Diabo is obtained. Many islands split up the falls, including several large ones. About 900 metres of the 2,7 kilometre length does not have water flowing over it. The first European to find the falls was the Spanish Conquistador Álvar Núñez Cabeza de Vaca, after whom one of the falls in the Argentine side is named.