Iguazú National Park (Argentina) was declared by UNESCO as Natural Heritage of Mankind in 1984. This natural sanctuary is located in the far north-east of the Republic of Argentina. Waterfalls of Iguazú (Iguassu) River consist of 275 single falls on the Argentinian and Brazilian side of the Iguazú River. There are 16 larger waterfalls on the Aregntinian side of 19 larger together. The waterfalls were most probably initially located at the confluence of the Iguazú 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.
The Guarani word 'Iguassu' means 'Great Water'. The river has it source in the moutains of Serra do Mar (Brazil) on the altitudse of 1300 m and runs to the west for 1320 km through the state of Paraná in Brazil before it flows into the Paraná 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 90 m). 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.