Iguazu Falls: The World's Largest Waterfall System
Along the border of Brazil and Argentina, the Iguazu River undergoes a dramatic transformation. It widens, slows, and then plunges over a basalt plateau, creating what is widely recognized as the largest waterfall system in the world. This natural wonder, known as Iguazu Falls, stretches approximately 2.7 kilometres across, forming a breathtaking spectacle of water and rock.
Geological Formation and Structure
The falls lie on a volcanic rock formation that has shaped the border between Argentina and Brazil. Over millennia, the river flow has carved through layers of hardened lava, resulting in a complex network of steps, islands, and separate curtains of water rather than a single continuous drop. The Iguazu River bends sharply before reaching the edge, contributing to the wide, curved shape of the falls.
Comprising around 275 individual cascades, the heights vary between 60 and 90 metres, depending on the section and season. At the centre sits Devil's Throat, a broad semicircle where water funnels into a narrow gorge and rises as a massive spray plume, often visible from aircraft and satellite images. The gorge beneath is narrow and steep, gradually lengthening due to ongoing erosion upstream.
Protected Ecosystem and Wildlife
On both sides of the river, national parks safeguard the surrounding subtropical forest, which has held UNESCO World Heritage status since 1984. This protected ecosystem supports over 2,000 species of vascular plants, thriving in the high humidity sustained by constant spray from the falls.
The rainforest is home to a diverse array of wildlife, including tapirs, giant anteaters, howler monkeys, ocelots, jaguars, and caymans. Birdlife is particularly active near the water, with species like the great dusky swift nesting behind the waterfalls. These dark, fast-flying birds fly directly through the falling water to reach hidden ledges, a risky behaviour that offers protection from predators in the forest.
Tourism and Visitor Experience
Tourism infrastructure surrounds the falls on both banks, with Argentina and Brazil maintaining viewing areas within their respective national parks. Wooden walkways extend over sections of the river, allowing visitors to approach several cascades closely. On the Argentine side, a one-kilometre walkway crosses calm water before reaching the edge of Devil's Throat, providing an immersive experience.
Hotels operate near the park entrances on both banks, and access routes are regulated to manage high visitor numbers throughout the year. Early morning light often reveals the scale of the spray column rising from the gorge, with mist casting faint shadows across the river surface before dissipating into the forest air.
The scale of Iguazu Falls becomes clearer from above, where white arcs of water contrast sharply with the deep green forest, highlighting its status as a global natural treasure.
