Walk right over the Devil's Throat
Argentina holds most of the roughly 275 falls that make up Iguazú, and its national park puts you among them rather than facing them. A small jungle train runs to the Garganta del Diablo, the Devil's Throat, where a long catwalk ends above a thundering U-shaped chasm lost in spray. The Upper and Lower Circuits loop over and beneath other falls, with coatis and butterflies along the way, and speedboats run right under the cascades. Allow a full day here, plus another for the Brazilian side.