Iguassu Falls sits along the borders of Brazil, Argentina and Paraguay and it’s absolutely massive. We gave ourselves two days to view the waterfall from both Brazil and Argentina (we popped into Paraguay too, but you can’t actually see the falls from there), although I’m sure you could easily spend more days exploring both sides fully.
Foz Do Iguaçu  Iguassu Falls From Brazil
The Brazilian side never seems to be overshadowed by Argentina in reviews. In my opinion the Brazilian side is better. If nothing else it gives you more views of the waterfall, without paying for a boat trip, than the Argentinian side.
Either way Iguassu is more impressive than Niagara Falls. I’ve been lucky enough to see Niagara too and was surprised at how built up it was; it seemed more like a theme park with all the bright lights than an impressive display of nature!
When you arrive at the Brazilian side you hop on a bus that takes you around the park. If you’ve bought extra activities you can hop off, but we headed straight for the route that lets you walk up to the falls.
Fortunately the day we were in Brazil it was sunny, giving us the perfect opportunity to get shots of that ever-present rainbow over the waterfall.
We then got absolutely soaked as we walked along the path leading into the centre of the waterfall!
When we visited the water was a lot higher, and muddier, than normal. There seems to have been tonnes of rain in Brazil this year (as we found when we visited the Pantanals), and some bridges had been broken, awaiting repair.
We stuck around hoping for a pretty sunset, but the clouds had closed in and this was the best we got.