At the border of which countries, there is a Iguazú Falls?

Iguazú Falls are waterfalls of the Iguazu River on the border of the Argentine province of Misiones and the Brazilian state of Paraná. Together, they make up the largest waterfall system in the world. Legend has it that a deity planned to marry a beautiful woman named Naipí, who fled with her mortal lover Tarobá in a canoe. In a rage, the deity sliced the river, creating the waterfalls and condemning the lovers to an eternal fall.