In this March 15, 2015 photo, tourists visit Iguazu Falls in Brazil. Spaniards came across the Iguazu Falls in 1541. The falls are part of the world's largest reservoir of fresh water, known as the Guarani Aquifer. They are in the middle of thick jungle that has more than 1,000 plant and hundreds of animal species. Millions of tourists visit the falls each year on both sides of the border. (Photo by Jorge Saenz/AP Photo)
