Iguazú Falls or Iguaçu Falls are waterfalls of the Iguazu River on the border of the Argentine province of Misiones and the Brazilian state of Paraná.
Together, they make up the largest waterfall system in the world.
The name "Iguazú" comes from the Guarani or Tupi words "y", meaning "water", and "ûasú", meaning "big".
The staircase character of the falls consists of a two-step waterfall formed by three layers of basalt. The steps are 35 and 40 m in height.
The Iguazu Falls are located where the Iguazu River tumbles over the edge of the Paraná Plateau, 23 kilometres (14 mi) upriver from the Iguazu's confluence with the Paraná River. Numerous islands along the 2.7-kilometre-long (1.7 mi) edge divide the falls into many separate waterfalls and cataracts, varying between 60 and 82 m (197 and 269 ft) high.
The Devil's Throat canyon is 80–90 m wide and 70–80 m deep. Left of this canyon, another part of the river forms 160-200 individual falls, which merge into a single front during flood stage. The largest falls are named San Martín, Adam and Eva, Penoni, and Bergano.