In this March 15, 2015 photo, a Japanese tourist holds on to her hat as she walks in the spray from the Iguazu Falls in Brazil. Spray from the falls douses the nearby viewing areas where some tourists don rain ponchos while others take off their shirts and dance and hug in the drenching mist. (Photo by Jorge Saenz/AP Photo)

In this March 14, 2015 photo, tourists take pictures from a viewing area at Iguazu Falls in Brazil. From walkways and bridges, viewers can count 270 water falls almost 100 meters (330 feet) high. (Photo by Jorge Saenz/AP Photo)

In this photo taken Sunday, March 15, 2015, tourists stand on a platform to get a better view of Iguazu Falls, in Foz do Iguazu, Brazil. Iguazu Falls, on the border of Argentina and Brazil, is part of the Guarani Aquifer, one of the world's major underground reserves of fresh water. (Photo by Jorge Saenz/AP Photo)

In this March 14, 2015 photo, a tourist poses for pictures doing a handstand at Iguazu Falls in Brazil. The falls 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)

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)

In this March 14, 2015 photo, Japanese tourist Hiromi Kanetake takes picturess as she stands in the spray of Iguazu Falls in Brazil. Kanetake summed up her feelings during her visit: “I'm so excited that my tears are mixing with the river water that floats in the air. I'm very happy that I came from so far away with my son Takayuki to see this”. (Photo by Jorge Saenz/AP Photo)

In this photo taken Sunday, March 15, 2015, tourists wear plastic ponchos as they walk in the spray of Iguazu Falls, in Foz do Iguazu, Brazil. Iguazu Falls, on the border of Argentina and Brazil, is part of the Guarani Aquifer, one of the world's major underground reserves of fresh water. (Photo by Jorge Saenz/AP Photo)

In this March 15, 2015 photo, tourists walk in the spray of Iguazu Falls in Brazil. From walkways and bridges, viewers can count 270 water falls almost 100 meters (330 feet) high. (Photo by Jorge Saenz/AP Photo)

In this March 14, 2015 photo, Brazilians Lilian and Edgardo kiss in the spray of Iguazu Falls in Brazil. Local indigenous legend has it that serpent god Boi, furious over a broken heart, created the falls by shattering the Iguazu river’s flow to prevent the maiden Naipu from escaping in a canoe with her lover Taroba. The legend says the rainbows that grace the waters are the souls of Naipu and Taroba reuniting. (Photo by Jorge Saenz/AP Photo)

In this March 15, 2015 photo, people wear plastic to try to keep dry in the spray of Iguazu Falls in Brazil. Spray from the falls douses the nearby viewing areas where some tourists don rain ponchos while others take off their shirts and dance and hug in the drenching mist. (Photo by Jorge Saenz/AP Photo)

In this March 14, 2015 photo, a tourist looks at Iguazu Falls in Brazil. Spaniards came across the Iguazu Falls in 1541. In Guarani, its name means “big water”. The falls are on the border between Misiones province in Argentina and Parana in Brazil. (Photo by Jorge Saenz/AP Photo)

In this Saturday, March 14, 2015 photo, Japanese tourists Hiromi Kanetake, right, and her son Takayuki, photograph themselves with a phone camera as they stand in the spray on the Brazilian side of Iguazu falls, behind, in Foz do Iguazu, Brazil. Iguazu Falls is located on Brazil's border with Argentina. (Photo by Jorge Saenz/AP Photo)

In this March 15, 2015 photo, a rainbow arches over the water at Iguazu Falls in Brazil. From above, the Iguazu Falls resemble a massive hole in a river surrounded by thick jungle. (Photo by Jorge Saenz/AP Photo)