The Cataratas del Iguazú (Iguazú Falls) are one of the wildest wonders of the world, with nature on the rampage in a unique show of sound and fury. The grandeur of this cinemascopic sheet of white water cascading in constant cymbal-banging cacophony makes Niagara Falls and Victoria Falls seem sedate. At a bend in the Río Iguazú, on the border with Brazil, the falls extend for almost 3 km (2 mi) in a 270-degree arch.

Iguazú consists of some 275 separate waterfalls - in the rainy season there are as many as 350 – that send their white cascades plunging more than 200 feet onto the rocks below. Dense, lush jungle surrounds the falls: here the tropical sun and the omnipresent moisture make the jungle grow at a pace that produces a towering pine tree in two decades instead of the seven it takes in, say, Scandinavia. By the falls and along the roadside, rainbows and butterflies are set off against vast walls of red earth, which is so ubiquitous that eventually even peso bills long in circulation in the area turn red from exposure to the stuff.