Corrientes is in the Mesopotamia region of Argentina.
Sometimes called the Pantanal of Argentina, Esteros del Ibera is in Corrientes. This is a wonderful place to see all sorts of crazy animals. Caimans (similar to alligators and crocodiles), Capybaras (world's largest rodent ~300 lbs), and anacondas (big snake) all call this area home. The area is basically a very alcaline shallow water area. There are "islands" in the water area that are just floating plant life.