The Garganta del Diablo is the climax of Iguazu. A 700-metre catwalk runs out across the upper river from the Brazilian-side rim of the canyon to a small platform set directly above the throat — a horseshoe-shaped chasm where fourteen separate cataracts pour eighty metres straight down into a wall of spray. The volume of water and the constant roar from below make it nearly impossible to hold a conversation on the platform.
The walk out from Estación Cataratas takes about half an hour at a steady pace, including the bridges across braided side channels of the river where you'll see large catfish in the slow water. The platform itself is usually thick with rainbows from mid-morning onwards. Go in the late afternoon for the lowest crowds and the most dramatic light.