Above the falls, the Río Iguazú itself is suitable for canoeing, kayaking, and other water sports; it should go without saying that there’s serious danger in getting too close to the falls. Below the falls, there are additional opportunities.

The principal tour operator is Iguazú Jungle Explorer (tel. 03757/421600, int. 582, tel./fax 03757/421696, www.iguazujunglexplorer.com), which has an office in the Sheraton and kiosks at the Portal Cataratas and at the Garganta del Diablo trailhead. Offerings include a 30-minute Paseo Ecológico (US$7) through the gallery forests and islands above the falls; a 15-minute Aventura Naútica (US$15) that approaches the Garganta del Diablo from below; and the Gran Aventura (US$30) that includes an eight-kilometer forest excursion by 4WD vehicle, a motorized descent of the lower Iguazú including two kilometers of rapids; and visits to the various falls.

Explorador Expediciones (Perito Moreno 217, Puerto Iguazú, tel. 03757/421632, www.rainforestevt.com.ar) has similar excursions and some more active offerings, such as white-water rafting and rappelling. It also has offices at the Sheraton (tel. 03757/421922) and a kiosk near the park entrance.