A boat carrying tourists is seen from the Argentine side of the Iguazu River at the Iguazu Falls in Puerto...
A boat carrying tourists is seen from the Argentine side of the Iguazu River at the Iguazu Falls in Puerto Iguazu June 15, 2014. Forming a border between Argentina and Brazil, the Iguazu Falls, South America's largest falls, attract more than 1 million visitors a year. REUTERS/Jorge Adorno (ARGENTINA - Tags: ENVIRONMENT SOCIETY TRAVEL)