Only about 20% of the park lies on the Brazilian side of the border. Thus, the vast majority of hiking trails, adventure tours and other activities begin on the Argentine side. There's still plenty to see and do among Brazil's beautiful corner of the falls, however.
You'll begin your visit at the massive Iguacu National Park Visitors Center, with interpretive displays about the region's natural history. Your ticket includes transport on air-conditioned buses that run between the entrance and trailhead every 15 minutes. There is only one waterfall trail, which runs a little over 2 km (1.25mi) along the river, with fantastic views of the Argentine side of the falls. The trail ends at Garganta del Diablo; take an elevator to the top of the falls for the postcard-perfect shot. The 9-km (5-mile) Black Well Trail (Trilha do Poço Preto) explores the jungle and river.
Thrill-seekers and budding photographers could consider a 10-minute helicopter trip above the falls and, for an extra fee, Itaipu Dam. The Helisul helipad is close to Visitors Center on the Brazilian side of the falls and costs about US$40 per person for ten minutes above Garganta del Diablo, more for longer journeys. You must have a minimum of three people to book the bird.
Though most boat tours leave from the Argentine side of the falls, folks staying in Brazil can book a few different river excursions, including the Macuco Safari. Begin with a 3km (2mi) ride in electrical vehicles through the rainforest, where guides explain the flora and fauna of the national park. From there, you can take tiny motorboats into the mist of the Three Musketeers and Devil's Throat, or even book a whitewater rafting trip back down the river. It's also possible to book fishing trips on the Parana River, where you'll still be able to hear the roar of the waterfalls.