Yasuní is roughly 10,000 square kilometers of rainforest between the Napo and Curaray rivers in Amazonian Ecuador, about 250 kilometers east of Quito. The park falls within the Napo moist forests ecoregion, and its position matters enormously. Few places on Earth lie where the Equator, the Andes, and the Amazon all converge. That convergence produces a small zone where amphibian, bird, mammal, and vascular plant diversity all hit their maximum levels in the Western Hemisphere simultaneously. The park breaks world records for local-scale tree, amphibian, and bat species richness. It is one of nine places on Earth with over 4,000 vascular plant species per 10,000 square kilometers. A single bat species, Lophostoma yasuni, is endemic and carries the park's name. A treefrog, Osteocephalus yasuni, does the same. The density of life here has a disorienting quality - the forest keeps surrendering organisms scientists have never described before.

Yasuní is the ancestral territory of the Waorani people, whose name for themselves means "the people," and who came into sustained contact with the outside world only in the mid-twentieth century. The park also shelters two groups who have not: the Tagaeri and the Taromenane, uncontacted peoples who have chosen isolation and whose territories shift with the rhythms of a forest they know better than any outsider. Oil roads cutting into their land are not an abstraction - they are the means by which disease, displacement, and violence arrive. In 1989, UNESCO designated Yasuní and the adjacent Waorani Ethnic Reserve together as a Biosphere Reserve, acknowledging that the forest and the people who live in it cannot sensibly be separated. When Indigenous communities spent more than a decade pushing for a national referendum on oil extraction, they were not arguing about economics. They were arguing for the conditions under which their neighbors could continue to exist.

Walk the riverbanks of the Tiputini or the Napo and the forest performs itself. Clay licks draw flocks of macaws and parrots at dawn - hundreds of birds descending for the minerals they cannot find in fruit. The park holds 596 documented bird species, roughly a third of all native Amazon birdlife. Giant otters, an endangered species endemic to these waters, hunt in the slow-moving igapos where Montrichardia linifera lines the banks. Canopy troops of monkeys move overhead: Ecuadorian white-fronted capuchins, Napo sakis, pygmy marmosets small enough to fit in a hand, brown woolly monkeys, Colombian red howlers whose dawn calls carry for kilometers. Beneath them, caimans drift in the rivers and an estimated 500 fish species navigate waterways that shift with the seasons. Over 150 amphibian species - a world record for comparable landscapes - announce the rainy months in a chorus that never quite resolves into silence.

The Ishpingo-Tiputini-Tambococha oil fields beneath the park hold about 40 percent of Ecuador's proven reserves. In 2007, President Rafael Correa proposed something unusual: the Yasuni-ITT Initiative, under which Ecuador would leave the oil untouched if the international community would compensate the country for half the estimated value - about $3.6 billion over twelve years. Jane Goodall, E.O. Wilson, Leonardo DiCaprio, and Al Gore endorsed the idea. By 2009, pledges reached around $1.7 billion. But the money never fully materialized, Correa insisted on Ecuador's sole control of the funds, and the initiative collapsed. Drilling began in 2016 and expanded into Indigenous buffer zones in 2019. Then, in August 2023, Ecuadorians did something no country had done before: they voted, in a national referendum, to halt the drilling. Petroecuador was ordered to dismantle its operations within one year, but as of 2025 compliance has been extremely slow — only one well among 247 had been closed, with the government seeking a five-year extension. The fight over the forest continues.