Researchers travelled 250 kilometres by boat up plus 20 kilometres on foot across mountainous jungle terrain to reach the specimen which is estimated to be at least 400 to 600 years old.
After three years of planning, five expeditions and a two-week trek through dense jungle, scientists have reached the tallest tree ever found in the Amazon rainforest.
The giant tree, whose top juts out high above the canopy in the Iratapuru River Nature Reserve in northern Brazil, is an angelim vermelho (scientific name: Dinizia excelsa).
"It was one of the most beautiful things I've ever seen. Just divine," forest engineer Diego Armando Silva of Amapa Federal University, who helped organise the trip, said.
"You're in the middle of this forest where humankind has never set foot before, with absolutely exuberant nature."
Measuring 88.5 metres (290 feet) tall and 9.9 metres (32 feet) around, researchers had first spotted the enormous tree in satellite images in 2019 as part of a 3D mapping project.
Amazon's giant trees
A team of academics, environmentalists and local guides first tried to reach the tree in 2019. But after a 10-day trek through difficult terrain, exhausted, low on supplies and with a team member falling ill, they had to turn back.
Three more expeditions to the reserve's remote Jari Valley region reached several other gigantic trees, but the enormous angelim vermelho remained elusive until the September 12-25 expedition.
Researchers travelled 250 kilometres (155 miles) by boat up rivers with treacherous rapids, plus another 20 kilometres on foot across mountainous jungle terrain to reach it.
After camping under the massive tree, the group collected leaves, soil and other samples, which will now be analysed to study questions including how old the tree is, why the region has so many giant trees, and how much carbon they store.
'Frightening levels of deforestation'
Around half of the weight of the region's giant trees is carbon absorbed from the atmosphere, fundamental in helping curb climate change, says Silva.
But despite its remoteness, the region's giants are under threat.
Angelim vermelho wood is prized by loggers, and the Iratapuru reserve is being invaded by illegal gold miners infamous for bringing ecological destruction, says Jakeline Pereira of environmental group Imazon, which helped organise the expedition.
"We were so thrilled to make this find," says Pereira. "It's super important at a time when the Amazon is facing such frightening levels of deforestation."
Over the past three years, average annual deforestation in the Brazilian Amazon has increased 75 percent from the previous decade.