Across the Iguazu River lies its Brazilian counterpart (Iguašu National Park). Both sites were declared World Heritage Sites by UNESCO, in 1984 and 1986.
The area of the park was inhabited 10,000 years ago by the hunter-gatherers of the Eldoradense culture. They were displaced around 1,000 CE by the GuaranÝ, who brought new agricultural technologies, and were displaced in turn by the Spanish and Portuguese conquistadores in the 16th century, though their legacy is still alive in this area (the name of the park and the river is GuaranÝ y guasu, "large water").
The first European to visit the zone was ┴lvar N˙˝ez Cabeza de Vaca, in 1542; Jesuit missions followed in 1609.