Parque Nacional Iguazú covers 67,000 hectares of subtropical forest on the Argentinian side of the river, designated a UNESCO World Heritage Site in 1984. The park is much more than its waterfalls: it preserves one of the last big tracts of Atlantic Forest, with jaguars, tapirs, and around 400 bird species recorded.
For most visitors, the park experience consists of the Upper and Lower Circuits, the Devil's Throat catwalk, and a ride on the small open-sided ecological train that links them — which is enough for one or two unhurried days. Buy tickets at the entrance gate; second-day visits are sold at half price if you keep your stamped ticket. The Sheraton hotel inside the park lets you arrive at the trails before the buses from town.