Iguazú means 'great water' in Guaraní, and the falls out-scale every superlative: a 2.7km arc of cataracts on the border of Argentina and Brazil, taller than Niagara and four times as wide. At the heart of it the Devil's Throat swallows half the river in a single roaring, permanently rainbowed abyss, ringed by subtropical rainforest.
