Iguazu Falls is 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 numerous separate waterfalls and cataracts, varying between 60 to 82 metres (197 to 269 ft) high. The number of these smaller waterfalls fluctuates from 150 to 300, depending on the water level. About half of the river's flow falls into a long and narrow chasm called the Devil's Throat (Garganta del Diablo in Spanish or Garganta do Diabo in Portuguese). The Devil's Throat is U-shaped, 82 meters high, 150 m wide, and 700 m long (269×490×2,300 ft). Place names have been given also to many other smaller falls, such as San Martin Falls, Bossetti Falls and many others.
About 900 meters (2,950 ft) of the 2.7-kilometre (1.7 mi) length does not have water flowing over it. The edge of the basalt cap recedes by 3 mm (0.1 in) per year. The water of the lower Iguazu collects in a canyon that drains in the Paraná River, a short distance downstream from the Itaipu Dam. The junction of the water flows marks the border between Brazil, Argentina, and Paraguay. There are points in the cities of Foz do Iguaçu, Brazil, Puerto Iguazú, Argentina, and Ciudad del Este, Paraguay, which have access to theIguazu River, where the borders of all three nations can be seen, a popular tourist attraction for visitors to the three cities
