Lonely Planet Writer

Mysterious boiling river found in Peruvian rainforest

Scientists have discovered what they believe is the largest thermal river on the planet.

Amazon rainforest, Peru in which the Boiling River flows
The Amazon rainforest in Peru in which the Boiling River flows. What is remarkable about the stream is that is non-volcanic with the nearest geothermal surface over 400 miles away Image by Craig Nagy / CC BY-SA 2.0

Hidden away in a deep rainforest in Amazonian Peru, the waterway runs piping hot for almost four miles and to a width of 80 feet. The Daily Telegraph reports that although such a river’s heat is not unusual around a geothermal surface, what is remarkable about  this case is that it is a non-volcanic area with the nearest such site over 400 miles away. In fact the Boiling River is one of three highly unusual non-volcanic waterways in the region – the others, much smaller streams, are known as the Salt River and the Hot River.

The bigger brook with a depth of up to 18 feet is fed by boiling and virtually boiling hot springs resulting in the river possessing several thermal waterfalls. One of those provides a 20ft-drop into a large thermal pool. In certain parts of the river, the water is so hot that animals that have inadvertently fallen into it and have been boiled to death.

A new campaign is seeking to have The Boiling River and it environs declared a  national monument to guard against the dangers of deforestation
A new campaign is seeking to have The Boiling River and it environs declared a national monument in Peru to guard against the dangers of deforestation CC BY-SA 2.0

Andrés Ruzo, the geoscientist who discovered the river and is leading the research says that when animals fall in, their eyes go blind almost immediately and their flesh is cooked from the inside out. Mr Ruzo explained that the reason the river boils is due to the fault-fed hot springs. The PhD student at Southern Methodist University in Dallas said he had initially heard about the unusual river from his father and later from his aunt, who claimed she had bathed in it. He said its discovery by him was a reminder that there are great wonders still to be discovered.

He launched the Boiling River Project to both protect and research the river and its environs. The local community sees the Boiling River as a sacred place. Mr Ruzo believes the biggest challenge facing the area is the current rate of deforestation and his aim is to have the river area declared a national monument in Peru. Although always attractive to a certain type of holidaymaker, it has also become a tourist curiosity and it is recommended that those considering a visit should liaise with Santuario Huistín or Mayantuyacu centres. The personnel in both have experience to provide tourists with detailed safety advice, travel tips and warnings about potential dangers surrounding the river.