There seems to be an unwritten international law that great waterfalls must be on the border of two countries. Niagara Falls, for instance, straddle the USA and Canada. If Iguazu Falls were there, rather than in Argentina and Brazil (and close to Paraguay), they’d be the most famous in the world. Instead, I’d never heard of them until my first trip to South America.
Another problem is that no photo can capture them all at once, because there are 275 drops over nearly three kilometres, with the Island of San Martín in the middle. But here are a few pictures anyway: