🇦🇷 Argentina · The Northeast and Mesopotamia
The Iguazú Falls are one of the most imposing natural spectacles on the planet: a system of more than 270 waterfalls spread over almost 3 km along the Iguazú river, deep in the Paraná rainforest. They're in the far northeast of Misiones province, on the border between Argentina and Brazil, and since 1984 they've been a UNESCO Natural World Heritage Site. In 2011 they were also chosen as one of the Seven Natural Wonders of the World.
The Argentine side, inside Iguazú National Park, holds about 80% of the falls and offers the most immersive experience: you walk among the falls, above and below them, thanks to a network of walkways and trails (the Upper Circuit, the Lower Circuit and the spectacular walkway to the Devil's Throat), plus the Rainforest Ecological Train that runs through the bush. The Brazilian side, on the other hand, hands you the great panoramic view of the whole thing from across the river. Ideally, if time allows, you see both.
Puerto Iguazú is the Argentine base for visiting the falls: a quiet town about 18 km from the park, with hotels for every budget, restaurants, agencies and direct flights from Buenos Aires and other cities. It's also where you organize the boat ride under the falls (Gran Aventura), rainforest trails like the Macuco, the visit to Isla San Martín and the crossing into Brazil. It's one of those destinations where nature, literally, leaves you speechless.
The falls were born of a geological accident on the basalt flows of the Iguazú river, whose Guaraní name means 'big water'. The European Álvar Núñez Cabeza de Vaca sighted them in 1542 and in 1934 Iguazú National Park was created to protect them. The Guaraní explain their origin with the legend of Naipí and Tarobá and the fury of the serpent M'Boi: the whole story, legend included, is on our history page.
Read the full history ↓The province of the Paraná rainforest and the red earth: home to the famous Jesuit-Guaraní missions, today a World Heritage Site, to the yerba mate that peopled its forests, and to the Iguazú Falls, one of the Seven Natural Wonders of the World.
Read the history of Misiones →No exact prices: a scale from $ (budget) to $$$$$ (luxury), with 2-3 options per category.
Origins, formation and what the sources say.
The Iguazú Falls are, above all, a story of rock and water. The Iguazú river rises in the Serra do Mar, in southern Brazil, and runs more than a thousand kilometers west until it flows into the Paraná river, at the point where Argentina, Brazil and Paraguay meet today. In its final stretch, the river crosses an enormous plateau formed by basalt flows: lavas that, in remote geological times (during the Jurassic-Cretaceous period), welled up without explosions, in gentle successive spills through fractures in the crust, and on cooling formed stacked layers of differing hardness.
The key to the landscape lies precisely in those layers. A fracture or fault created an abrupt step in the river bed, and the water began to plunge over it. Since the basalt flows are not all equally resistant, erosion worked the soft rock faster than the hard, carving out the great amphitheater of falls we see today: more than 270 cascades spread over almost three kilometers. The most imposing drop is the Devil's Throat, a horseshoe of about 80 meters where the river concentrates its greatest force. What's more, the falls keep retreating upstream, extremely slowly: erosion never stops.
The name says it all. 'Iguazú' comes from the Guaraní 'y' (water) and 'guasu' (big): 'big water'. For the Guaraní peoples who inhabited the Paraná rainforest, this place was not just a natural feature but a site charged with sacred meaning, as their founding legend tells.
Long before any geological explanation, the Guaraní already had their own version of the origin of the falls, and it is one of the most beautiful and tragic legends in the Americas. The story tells that in the Iguazú river lived M'Boi (also written Boi or Mboí, 'serpent' in Guaraní), a serpent god, son of Tupá, who ruled over the waters. Every year the tribe had to offer him a beautiful maiden in sacrifice, throwing her into the river to calm his fury and avoid his curses.
One year the chosen one was Naipí, a young woman with long hair, so beautiful that even the serpent god wanted her for himself. But Naipí was in love with Tarobá, a brave young chief of another tribe. The night before the sacrifice, the two lovers fled together, paddling a canoe downriver, trying to escape their fate. M'Boi, who saw everything, flew into a rage. With his enormous body he sank into the earth and split the river's course in two, tearing open an abyss: that, according to the legend, is how the falls were born, right in front of the escaping canoe.
The punishment was eternal. The serpent turned Tarobá into a tree that grows at the edge of the falls, and Naipí into one of the rocks forever beaten by the water, while her long hair became the cascades themselves. Then M'Boi plunged to the bottom of the Devil's Throat, from where he watches the lovers so that they may never be reunited. The Guaraní say that only now and then, when the sun comes out through the spray, the rainbow defies the serpent and throws a bridge that joins Naipí and Tarobá once more, for an instant.
The first European to leave a written account of the falls was the Spanish conquistador and explorer Álvar Núñez Cabeza de Vaca, in 1542. He was marching overland from the Atlantic coast, leading an expedition that was trying to reach Asunción, when he came upon the spectacle of the Iguazú river plunging into the rainforest. Impressed, he named the whole thing the 'Saltos de Santa María', although that name never took hold: over time the Guaraní original, Iguazú, prevailed.
Over the following centuries, the area stayed on the margins of colonization. It was dense rainforest, far from the main centers, in a region of vague borders between the Spanish and Portuguese empires. The Guaraní peoples went on living in the bush, and further south, on the Paraná river, the Jesuits raised their famous missions (such as San Ignacio Miní). But the falls themselves remained all but inaccessible and little visited for a long time, protected by their own remoteness and by the thickness of the Paraná rainforest.
Only in the 20th century did the Argentine state step in to protect the falls. On 9 October 1934, during the presidency of general Agustín P. Justo, Law 12103 was passed, creating the National Parks Directorate and, with it, two of the country's first national parks: Iguazú National Park and Nahuel Huapi National Park. The decisive push had come a few years earlier from Francisco Moreno himself, who from the start of the century had argued for preserving these landscapes from private exploitation, and from the engineer Carlos Thays, who designed the first trails. The aim was to conserve the setting of the falls and the extraordinary biodiversity of the Misiones rainforest around them, one of the richest environments on the continent, with a protected area of more than 67,000 hectares on the Argentine side.
Since then, the park has built up the infrastructure that today lets you tour the falls without damaging them: the first wooden walkways from the early 20th century were replaced after the great flood of 1992 —which swept away much of the existing structure— by today's metal walkways, far more resistant to the river's floods. The Rainforest Ecological Train was also built, replacing an older, more polluting diesel train, and visitor centers, interpretive trails such as the Macuco and a visitor management system designed to minimize human impact on such a fragile ecosystem were added. On the Brazilian side the Parque Nacional do Iguaçu was created, also in the 1930s (1939), so the wonder has been protected by both countries ever since, in one of the few binational natural areas on the continent.
International recognition came in 1984, when UNESCO declared Iguazú National Park a Natural World Heritage Site, for its scenic beauty and its enormous biological diversity (the Brazilian park received the same distinction in 1986). And in 2011, after a worldwide vote organized by the New7Wonders foundation that gathered millions of votes from around the planet, the Iguazú Falls were named one of the Seven Natural Wonders of the World, alongside the Amazon rainforest, Ha Long Bay and other emblematic landscapes. Today the park preserves, besides the landscape, rainforest wildlife that includes the jaguar (seriously endangered, with reintroduction programs active in the area), the tapir, capuchin monkeys, coatis, more than 400 bird species and some 800 butterfly species, in what is one of the last great remnants of the Paraná rainforest, an ecosystem that once covered much of southern Brazil, eastern Paraguay and northeastern Argentina and that today survives in barely a scattering of fragments.