Introduction to Devil's Throat: The Iguazu Falls waterfall is formed when the Iguazu River, which flows west and then north, falls into a wide gap from the edge of the Paraná Plateau before entering the canyon. Waterfalls are distributed on both sides of the canyon. Argentina and Brazil are bounded by this canyon. The waterfall scenery seen in Argentina and Brazil is also completely different. The top of the canyon is the center of the waterfall, where the water flow is the largest and most powerful, and is known as the "Devil's Throat."