Iguazú Falls or Iguaçu Falls are waterfalls located on the border of the Argentina and Brazil. They are the largest waterfalls system in the world and recognised as one of the seven natural wonders of the world. The number of waterfalls fluctuates from 150 to 300, depending on the water level. The falls on the Iguaçu River have a flow capacity equal to three times that of Niagara Falls.

Foz do Iguaçu is named because it sits at the mouth of the Iguaçu river, discharging into the Paraná river, at the border between Brazil, Paraguay and Argentina. For most of its course, the river flows through Brazil; however, most of the falls are on the Argentine side. Approximately half of the river's flow falls into a long and narrow chasm called the Devil's Throat, Garganta do Diabo.