The Iguaçu Falls are made up of about 275 cascades and rapids in the Iguaçu River, which is located in the Parana River Basin. It is located between the Iguaçu National Park — in the State of Paraná, Brazil — and the Iguazú National Park in Misiones, Argentina. The total area of both parks corresponds to 250 thousand hectares of subtropical forest and is considered a Natural World Heritage Site.
The Argentine National Park was created in 1934 and the Brazilian one in 1939, aimed at managing and protecting the source of water that represents the waterfalls and the surrounding environment. The national parks were acknowledged as World Heritage Sites in 1984 and 1986. Since 2002, the Iguaçu National Park is one of the Brazilian geological sites. Historically, the first European to find the Iguaçu Falls was the Spanish Álvar Núñez Cabeza de Vaca, in 1542.
Source: Wikipedia with revision.
