The Iguazu Falls, one of the 7 wonders of the planet, are the biggest in the world with their 275 cascades on 3 kilometers. But, how to reconcile today this ecological treasure with the development of tourism, in a region in full economic boom? Thanks to the creation of several national parks in Argentina and Brazil, they are in the heart of a vast forest with unique biodiversity. The area of the falls is home to 422 species of birds, from the majestic toucans to the great dusky swifts, which nest behind the falls, or the grey-fronted guans, essential for the regeneration of the forest