Doing a pre c cruse to iguasu(spelling??) falls if a sight not to be missed.You would fly from rio or buenas aires to the falls and stay overnight.It would be costly but the falls are spectacular-makes niagra look like bath tub.They are located in jungle and flying in they are so hugeit is a sight not to be forgotten.Some cruislines have a pre cruise which include this.
most ports are small --one the captain even said i don't know why we stop here but you pick up some toiletries
this port has an excursion going to national park and boat trip out to some island with lots of seals walruses etc
we did not do this tour--but heard it was graet