I visited the rainforest in Brazil (Iguazú Falls / Foz do Iguaçu) a few years ago and saw literally dozens of species of butterflies of every size and color. It was truly incredible. Not to mention the falls themselves and the rest of the flora and fauna. The rainforest is amazing!
Used to be like that between Myanmar and Laos when descending the Mekong from China to Thailand. These days you'd be lucky to see one: development on both sides, particularly clear-felling for rubber (the price of which has now crashed), has totally destroyed the biodiversity.