The bus for our tour to the Argentine side of the falls turned up a little early at 7:50, and off we went. It soon dawned on us that there would be no more passengers today and that this had turned into a private tour. The guide shepherded us through the border into Argentina and not long after 9:00 we were at the parque nacional, had bought our entry tickets and were on the mini-train that took us to the beginning of the 1 km walkway out to the top of Guargantua Diablo, the largest of the falls. We saw this same waterfall from below when we visited the Brazil falls. There was a light fog early in the day so we did not get very good photos of this fall.