It is the only river of its kind in the world!
According to Peruvian locals, legend has it that there was a river so hot that it boiled from below — so scalding it could even kill!

Andrés Ruzo, a Peruvian geoscientist, had been fascinated with the myth since childhood, but it wasn’t until he was completing his PhD project on geothermal energy potential at the Southern Methodist University that he began to think that the river could actually be real.

However, his idea was met by skepticism and considered preposterous by his senior colleagues. It would take an enormous amount of geothermal heat to boil even a small section of a river, and the Amazon basin lies 700 kilometers (435 miles) from any active volcanoes. One of Ruzo’s advisors even told him to stop asking “stupid questions” if he wanted to finish his PhD.

But when Ruzo went home for the holidays, his mother told him that not only did the river exist, but she and his aunt had actually swum in it. So, Ruzo along with his aunt, hiked into the Amazon rainforest where he saw the legendary river with his own eyes.

The Shanay-timpishka river is actually a sacred geothermal healing site of Mayantuyacu — Asháninka people — and protected by a powerful shaman.

Much to Ruzo’s disbelief, the river was steaming hot. “When I saw this, I immediately grabbed for my thermometer,” said Ruzo in a TED Talk back in 2014. “The average temperature in the river was 86 degrees Celsius [187 Fahrenheit], not quite boiling but definitely close enough … It’s not a legend.”

However, its temperature was not the most puzzling part — its size was. Hot springs aren’t uncommon, and thermal pools get to these temperatures in other parts of the world.

However, nothing anywhere in the world comes close to the magnitude of the river — it is up to 25 meters (82 feet) wide, 6 meters (20 feet) deep, and runs burning hot for an incredible 6.24 kilometers (4 miles).

With permission from the shaman, Ruzo spent the last five years studying the river, its surrounding ecosystem, and its water in the lab. With the help of the National Geographic Young Explorers Grant, Ruzo determined that it is not the sun that boils the water but fault-fed hot springs.

Chemical analysis revealed that the water in the river originally fell as rain, then seeped into the ground as it headed toward the river where it was heated by Earth’s geothermal energy, and it eventually emerged in the Amazon through faults to create the boiling river.

Ruzo, along with biologists Spencer Wells and Jonathan Eisen sequenced the genomes of the microbes living in and around the river. Amazingly, they discovered brand new species that are able to survive the extreme heat.

But not all animals can survive water that hot. Unfortunately, Ruzo regularly saw animals fall in and slowly boil to death. “The first thing to go are the eyes,” he explained in his TED Talk. Eventually, the animals can no longer swim, and water fills their mouths and lungs, causing them to be cooked from the inside out. Just awful.

Surprisingly, people do swim in the river, but only after heavy rains have diluted it with cold water. More often than not, the water is used for cooking and to make tea.

Ruzo continues to study the Shanay-timpishka river, but his focus is now on its protection and conservation. He released a book called The Boiling River and hopes it will inspire others to also protect it from loggers and developers.

Here is a teaser video showing this steamy natural wonder.