Peru amazon
The river is in the Peruvian Amazon (representational image)EdwinJs

A mythical boiling river that stretches for four miles has been discovered in the Peruvian Amazon. The river, at Mayantuyacu, was discovered by geoscientist Andrés Ruzo after being told tales about its existence by his grandfather.

the boiling river
Simon & Schuster/ TED

Ruzo said Spanish conquistadors exploring the Amazon after killing the last Inca emperor came across extreme dangers – including man-eating snakes and a river that boiled from below, as if lit by a fire. But the Amazon basin is nowhere near any active volcanoes, and the geothermal heat needed would be so tremendous the very idea of the boiling river's existence was dubbed ludicrous by Ruzo's university lecturers and colleagues.

A report on his find by Gizmodo tells how Ruzo asked his aunt who had visited the river about its whereabouts. Deep in the rainforest, at the geothermal healing site of Mayantuyacu, he found it. The river is 80ft wide, 20ft deep and is extremely hot for about a four-mile stretch. One part even boils.

Previously, the existence of hot springs in the Amazon has been documented, but there is nothing written about a boiling river. So Ruzo has undertaken the task of carrying out detailed geothermal studies on the river as well as collaborating with ecologists to investigate the wildlife living in the boiling water. Any extremophiles living in the extreme temperatures could provide clues about early life on Earth.

However, he also wants to save the river from illegal logging and developers. "In the middle of my PhD, I realized, this river is a natural wonder. And it's not going to be around unless we do something about it.

"You're surrounded by the sounds of the rainforest. You feel this water surging past you and plumes of vapour coming up. It's truly a spectacular place. The planet's gotten small, and natural wonders like this are few and far between."

Ruzo's research, which is being backed by a National Geographic grant, appears to show the water is being boiled by hot springs fed by faults. The water in the river originally fell as rain and Ruzo believes this happens far upstream, after which it trickles down into the ground, where it is heated and emerges in the Amazon. This sort of hydrothermal system has never been found anywhere else.

To pique interest in the boiling river, Ruzo has now released a book on its discovery and importance and appeared in a Ted Talks film. The Boiling River: Adventure and Discovery in the Amazon was released on 16 February and is available through Amazon.