@andrewk81--
She's from Denmark. It's called "nationality".
"if you don't know the answer...."
@MSivesgaard--
There are local public buses to get between the Argentine and Brazilian sides of the park and the towns.
One bus route runs from the bus station in Puerto Iguazu to the bus depot in Foz do Iguacu. You do have to stop at the border to show your documents, although I believe Danish passport holders don't need a visa to Brazil, nor an Argentine reciprocity fee receipt.
Another bus route runs from the town to the park entrance, passing the airport. This is true for both sides.
The town/park route and the town/town route do intersect outside town, but it may be clearer to go to the bus station/depot on the town/town bus, and back out to the park on the other bus, than to figure out the intersection point just to save a few minutes.
The views, those iconic ones from the photos you may have seen, are from the Brazilian side, looking across at most of the falls. The walk there can be done comfortably in a few hours. The Argentine park offers a different experience, or experiences. I recommend the thrilling boat ride under the falls (cheaper, I have heard, from Argentina than the Macuco from Brazil), and being up close and personal with the macaws at the Bird Park.
