Iguazu Falls are an amazing spectacle, located on the border between Argentina, Brazil the falls can be visited from either side. In order to see the full falls visit the Brazilian side, to have close up views of the falls visit the Argentinian side.
The falls are located on the Iguazu River and can be accessed from Foz do Iguaçu in Brazil and Puerto Iguazú in Argentina, as well as from Ciudad del Este Paraguay
The falls can be visited from the Argentinian or Brazilian side. You can fly into Foz do Iguaçu Airport (IGU) on the Brazilian side, and Cataratas del Iguazú (IGR) on the Argentine side.
To visit the falls make sure to book a guide, they can meet you at the airport and help you get around. From Buenos Aires you a can make a day trip out of it.
Last time we visited we hopped on a Aerolinas Argentina flight from EZE to IGR, arranged for a guide from Tours by Local who showed us around the park and explained the falls, flora and fauna. It made for a long day (6am to 10pm) but was well worth it.