Foz do Iguazu, in Brazil, is the best city to stay if you want to visit the waterfalls. One park (the biggest) is in Argentina. One in Brazil and a bit in Paraguay. Note, ciudade del este, Paraguay is very busy... Not very nice (my opinion...)
Quick Tips:
Use sun protection. The entrance is expensive for the Argentina side. But it`s also by far the nicest part.Best Way To Get Around:
Get a bus or taxi to the park.