Once you're in the park and ready to visit the falls, take the Parque Nacional do Iguaçu bus to the third stop at Belmond Hotel das Cataratas. Here you can pick up the main waterfall observation trail, Trilha das Cataratas ('Waterfall Trail'), a 1200m trail following the shore of the Iguaçu River, terminating at the Garganta do Diabo.
It's a 1.5km walk down a paved trail with brilliant views of the falls on the Argentine side, the jungle and the river below. Every twist of the path reveals a more splendid view until the trail ends right under the majestic Salto Floriano, which will give you a healthy sprinkling of water via the wind it generates. A catwalk leads out to a platform with majestic vistas, with the Garganta do Diabo close at hand, and a perspective down the river in the other direction. If the water’s high, it’s unforgettable; a rainbow is visible in the spray on clear afternoons.
An elevator heads up to a viewing platform at the top of the falls at Porto Canoas, the last stop of the double-decker buses. Porto Canoas has a gift shop, a couple of snack bars and an excellent buffet restaurant.