Iguazu Falls: One of the Most Famous Waterfalls in the World

Location: Iguazu Falls are located on the Iguazu River, directly on the border between Argentina and Brazil and close to the tri-border area with Paraguay. On the Argentine side, they lie in Misiones Province, while on the Brazilian side they are in the state of Paraná. Here, the river forms the international border and also separates Argentina’s Iguazú National Park from Brazil’s Iguaçu National Park.

Significance: Iguazu Falls are among South America’s best-known natural wonders and rank among the most famous waterfalls in the world. Every year, millions of people visit the two national parks on the Argentine and Brazilian sides. In 2011, the falls were also selected as one of the New7Wonders of Nature in a worldwide vote.

Geological Formation: The geological foundations of Iguazu Falls were created around 135 million years ago, when massive lava flows covered the region with thick layers of basalt. The waterfalls themselves formed much later. Around 1.5 million years ago, the edge of the falls was still located near the point where the Iguazu River meets the Paraná River. Since then, the water has gradually eroded the rock at the edge, causing the falls to retreat slowly upstream. This process of headward erosion created a canyon around 21 kilometres long. Even today, the edge of the falls continues to move upstream by approximately 1.4 to 2.1 centimetres per year.

Impressive Scenery: Across a width of around 2.7 kilometres, the Iguazu River plunges over roughly 275 individual waterfalls and cascades. Some reach heights of around 80 metres and create vast clouds of spray. Their setting in the middle of dense subtropical rainforest makes the scenery even more dramatic. The deep green vegetation forms a striking contrast with the thundering masses of water.

Enormous Volumes of Water: On average, more than 1,400 cubic metres of water per second rush over Iguazu Falls. After heavy rainfall, that volume can increase several times over within a short period. During an exceptional flood in June 2014, a flow of around 45,700 cubic metres per second was recorded. The figure gives a vivid sense of the immense power of the Iguazu River.

Devil’s Throat: Devil’s Throat is the most spectacular and best-known section of Iguazu Falls. Here, enormous volumes of water plunge into a horseshoe-shaped gorge, creating dense spray and a deafening roar. On the Argentine side, a long walkway crosses the river and leads to an observation platform right at the edge of the falls. From there, visitors can experience the immense force of the water at remarkably close range.

Rainbows: Spectacular rainbows can often be seen above Iguazu Falls. The fine spray fills the air with countless tiny droplets that refract the sunlight. Under the right lighting conditions, vivid arcs of colour appear above the waterfalls and the surrounding rainforest.

Tourist Activities: Boat trips are particularly popular, taking visitors extremely close to the thundering waterfalls and making their immense power directly tangible. On the Brazilian side, helicopter sightseeing flights are also available and offer impressive views of the full scale of the falls. Those who prefer to explore on foot can follow numerous trails and walkways through the subtropical rainforest, leading to a variety of viewpoints.

National Parks: Iguazu Falls are surrounded by two major protected areas. Argentina’s Iguazú National Park was established in 1934, followed by Brazil’s Iguaçu National Park in 1939. Together, they protect a particularly valuable section of the Atlantic Forest, home to an extraordinary diversity of plants and animals. The Argentine national park has been a UNESCO World Heritage Site since 1984, while the Brazilian national park was added in 1986.

Flora: Dense subtropical rainforest surrounds Iguazu Falls and is home to more than 2,000 plant species. Ferns, palms, lianas, orchids, and bromeliads thrive among the tall trees. The constant spray creates an exceptionally humid microclimate, especially on the islands and along the riverbanks. As a result, the vegetation directly around the falls is particularly lush and diverse.

Fauna: The area around Iguazu Falls is home to an exceptionally diverse range of wildlife. Coatis, toucans, monkeys, and colourful butterflies are especially common. Great dusky swifts are particularly remarkable because they even roost behind the falling curtains of water. Caimans, tapirs, and anteaters also live in the rivers and more remote parts of the forest. Rare big cats such as jaguars and ocelots are also native to the protected national parks.

Best Time to Visit: Iguazu Falls are worth visiting at any time of year. However, the period from March to May is especially pleasant. After the hot summer, temperatures become noticeably milder while the falls usually still carry plenty of water. April and May in particular often offer ideal conditions, with comfortable temperatures, lush green rainforest, and impressive water levels.

History of Discovery: Long before the arrival of Europeans, the region around Iguazu Falls was inhabited by Indigenous peoples. The Guaraní had lived here for generations before European colonisation began, farming, hunting, fishing, and using the resources of the rainforest. Several Mbyá Guaraní communities still live around Puerto Iguazú and near the national park today. The first known European description of the waterfalls came from the Spanish explorer Álvar Núñez Cabeza de Vaca, who reached them in 1542 while travelling to Asunción, where he was due to take up his position as governor. He named the falls Santa María. The name did not last, however. Instead, the Indigenous name Iguazú, which was already in use, remained.

Name: The name Iguazú comes from Tupi-Guarani and roughly means “great water”. In Argentina, the Spanish spelling Iguazú is used, while in Brazil the Portuguese form Iguaçu is used.

UNESCO World Heritage: Iguazu Falls lie within two directly adjoining UNESCO World Heritage Sites. The Argentine national park was added to the World Heritage List in 1984, followed by the Brazilian national park in 1986. In the Brazilian national park, the so-called Estrada do Colono, an approximately 18-kilometre road through the protected area, became a major source of conflict. It was closed in 1986, but from 1997 onwards it was repeatedly reopened and used illegally. Because this posed a threat to the protected area, UNESCO placed the national park on the List of World Heritage in Danger in 1999. In June 2001, the road was permanently closed. The authorities made the route impassable, removed three bridges, and planted thousands of native trees to help the damaged rainforest recover. Later that same year, UNESCO removed the national park from the List of World Heritage in Danger.