The Iguassu Waterfalls are situated inside
the Iguassu National Park.
The Iguassu National Park (Brazil) was created by Brazil federal decree on the 10th January 1939. The Park contains the area of 185,000 hectares of subtropical rain forest. The national park was declared by UNESCO as Natural Heritage of Mankind site in 17th November 1986. Waterfalls consist of 275 single falls on the Brazilian and Argentinian side of the Iguassu River. The waterfalls were most probably initially located at the confluence of the Iguaz and Parana Rivers some 20,000 years ago, but erosion has caused them to recede 28 km upstream to their present location at the altitude of 150 m. The area of waterfalls is part of a large plateau formed by basaltic lavas during the Mesozoic Era, more than 150 million years ago. Lava surfaced through tectonic faults and cracks, without formation of volcanic cones, and covered some one million square kilometres.
There are only 3 larger waterfalls on the Brazilian side of 19 larger together. The Guarani word 'Iguassu' means 'Great Water'. The river rises in the area of Serra do Mar and runs for 1320 km through the state of Paran before it flows into the Paran River at Puerto do Iguazu where are three borders of Argentina, Brazil and Paraguay.
The width of the falls (2700 m) is 800 m on the Brazilian side and 1900 m on the Argentinean side. Including a rapid above the falls, the height is 72 m (their height varies between 40 and 90m). Depending on the season of the year (rain fall) the water flow varies between 300 cubic metres/sec and 6500 cubic metres/sec with an average flow of 1500 cubic metres/sec.