Iguazu Falls Historical Timeline

Guaraní origins and the legend of Naipi

The Guaraní people had lived in the region for thousands of years before any European saw the falls, and it's their language that gives Iguazu its name -- "y" for water and "guasu" for big or great. A Guaraní legend tells of a river god, M'boy, who wished to marry a woman named Naipi; when she fled downriver by canoe with her lover Tarobá, the enraged god sliced the riverbed apart, creating the falls and condemning the two lovers to fall forever.

European encounter

The Spanish conquistador Álvar Núñez Cabeza de Vaca is generally credited as the first European to see the falls, in 1541, initially naming them Santa María Falls before the Guaraní name Iguazú took hold in the years after.

How the falls were formed

The falls owe their existence to volcanic activity roughly 120 million years ago, when massive eruptions spread thick basalt flows across what's now the Paraná Basin, covering parts of present-day Brazil, Paraguay, and Argentina. Over millions of years, the Iguazu River has worn away softer rock beneath this hard basalt layer, undercutting it to create the horseshoe-shaped series of drops that make up the falls today.