What to do in Iguazu Falls?

One must visit both sides of Iguazu Falls. Argentina side and Brazil side are wonderful, angles are different, perspective is different, light is different and the way people see them is also different. 
There are two national parks and the falls are in the middle, the Iguassu River is the border.  Se the Iguazu Falls location on the map. 

Best time to visit the Brazil side of Iguazu Falls? 
Some books mention that you that the best time is visiting the falls in the morning but in the winter-time, it is worth to visit it around mid-day. There is no much sunlight in the winter and also the sun is moving in a different way. As people arrive at the falls in Brazil, they spend like two hours to see it.  (07/29/2020)