We visited the Iguassu Falls in 2005 - again the trip was organised by Travelbag, and included guided visits to both the Brazilian and the Argentinian sides of the Falls, along with a very scary boat trip right up to the foot of the falls (we got exceedingly wet!) and a rainforest safari.  The photos cannot begin to convey the sheer spectacle and the thunderous sound of these magnificent falls, which are taller than Niagara and wider than Victoria.