The waterfall system consists of 275 falls along 2.7 kilometers (1.67 miles) of the Iguazu River.
"The first European to find the falls was the Spanish Conquistador Álvar Núñez Cabeza de Vaca in 1541, after whom one of the falls in the Argentine side is named. The falls were rediscovered by Boselli at the end of the nineteenth century, and one of the Argentine falls is named after him."
Some of the individual falls are up to 82 meters (269 ft) in height, though the majority are about 64 metres (210 ft). The Devil’s Throat (Garganta del Diablo in Spanish or Garganta do Diabo in Portuguese), a U-shaped, 82-meter-high (269 ft) , 150-meter-wide and 700-meter-long (490 by 2,300 feet) cataract, is the most impressive of all, marking the border between Argentina and Brazil. Two thirds of the falls are within Argentine territory.
About 900 meters (0.56 miles) of the 2.7-kilometer length (1.67 miles) does not have water flowing over it. The edge of the basalt cap recedes only 3 mm (0.1 in) per year. The water of the lower Iguazu collects in a canyon that drains into the Paraná River at Argentina, shortly downstream from the Itaipu dam.
Iguazu currently has the greatest average annual flow of any waterfall in the world. The water falling over Iguazu in peak flow has a surface area of about 40 Ha (1.3 million ft²) whilst Victoria in peak flow has a surface area of over 55 ha (1.8 million ft²). By comparison, Niagara has a surface area of under 18.3 ha (600,000 ft²).
Taller than Niagara Falls and twice as wide, Iguazu Falls are the result of a volcanic eruption which left a large crack in the earth. During the rainy season of November – March, the rate of flow of water going over the falls may reach 450,000 cubic feet (12,750 cubic m) per second.
