You can catch a taxi at the airport for the hotel. When you arrive at the park, you pay entry fees for one day and get driven to the Sheraton. This is the only hotel on the Argentine side that is
in the park.
When the park opens in the morning, you are already there - while people are arriving at the gate and eventually clambering on the train or walking the treail, you are in the park walking the trails, seeing monkeys, toucans, parrot flocks most daytrippers will not see.
If you are a walker, you will really enjoy yourself and have many views. The boats across to the island, more views, are free. You can also walk to the middle train station and take it out - but we enjoyed the walks. There is about four times more to se and do on the Argentine side than the Brazilian side; we enjoyed three days here amnd one day with a driver to the Brasil side, including the bird park, falls and helicopter ride, and a meal in a churrascaria in Foz do Iguaçu.
Brazil charges Americans like a wounded bull for their visa - only because it is reciprocity with the U. S. fees. You can request a multiple entry visa good for five eyars - that's what we had in our old passport (so, we have to get a new one...)
The hotel charges like a bull for things like bottled water - you can get very large bottles for a much lower price if you go to town, not to mention souvenirs, etc. But it's worth it - the second-growth tropical forest is very nice (lots of critters - birds, amphibians, insects...) the many spectacular views of the falls - well, it makes one wonder what the big deal is about that tiny little Niagara...
