Alvãr Nuñes Cabeza de Vaca, a great Spaniard explorer who was born in Jerez de la Fronteira, southern Spain, in 1507 and passed away in Seville in 1559, was the discoverer of the Falls. Before sailing the Iguaçú and Paraná rivers, he had been in North America, where the traveled Mississippi, Arkansas, Colorado, New Mexico and Arizona and reached California in 1536.

On January 31, 1542, Cabeza de Vaca led a Spaniard expedition that traveled through the region, inhabited by the Caiagangue and Tupi-Guarani Indians, towards the settlement of Assumption, which was a strategic point to enable Spaniards to reach the Inca Empire. Among the first obstacles faced during the trip, as he canoed down river in search of a route to Assumption, Paraguay, the discoverer could not keep from shouting "Holy Mary, how beautiful it is!!!" as he saw the Falls for the first time. Thus, counting on luck and his skills to avoid being entrapped in the river, Cabeza de Vaca became known in history for his feat and his famous words. He was the first white, Christian and noble man to see the Iguaçú Falls. Nevertheless, after seeing the water plunging into the abyss, he christened them Waterfalls of Saint Mary. Later on, the Falls adopted their definitive name, Iguaçú Falls. IGUAZU means "big water" to the guarani Indians that have inhabited the region for more than two thousand years.

Beautiful and impossible to reach, the region would again be news in the XVIII century, when the Jesuits established an Indian catechizing facility. Meanwhile, the region remained being disputed by Spaniards and Portuguese. The territory boundaries were only settled after Argentina, Brazil and Paraguay achieved their independence. During the first decades of this century, the region remained isolated and unpopulated, although the few visitors who ventured there did not spare their praise to the exuberance of the region.

Alberto Santos Dumont, the aviation pioneer, was one of the enthusiasts who visited the Falls in 1916 and was so impressed by them that was determined to fight for the creation of a public park in the area. On July 28 of the same year, Affonso Alves de Camargo, President of the Province of Paraná expropriated the land where the Falls are located.