Taller than Niagara Falls, twice as wide with 275 cascades spread in a horsehoe shape over nearly two miles of the Iguazu River, Iguazú Falls are the result of a volcanic eruption which left yet another large crack in the earth. During the rainy season of November - March, the rate of flow of water going over the falls may reach 450,000 cubic feet (12,750 cubic m) per second.