This incredible natural phenomenon was discovered in 2011 by a group of researchers from the geophysics department of the National Observatory of Brazil. The group was led by Valiya Mannathal Hamza and for that reason, the river bears his name. 
![rio-amazonas-rio-hamza-2-compressor.jpg](https://steemitimages.com/DQmcdnf8KG62Z7Pccsz9RsQaetJaYX8WDhuDYNMY97czwb4/rio-amazonas-rio-hamza-2-compressor.jpg)

Under the Amazon lies the "Hamza River", probably the longest underground river in the world.
Like the Amazon River, the Hamza River is born in the Andes mountain range in Peru, with an extension of about 6,800 kilometers.

Hamza runs very slowly between the sediments to a depth of 4 kilometers underground. While the Amazon flows at a speed of 1 meter per second, the Hamza does it at an average of 50 meters per year, much slower than the rest of the rivers. Such characteristics make scientists debate if the phenomenon could really be considered a river. 
The groundwater flow is vertical, but changes direction and becomes horizontal at greater depths.

Although some claim that it can not be considered a river as such, our planet has many surprises for us and the Hamza River is proof of that ...

![Rio-Hamza.jpg](https://steemitimages.com/DQmenya5xet4AA9fTSvfMVNVFSTbAWoa32sYKWXyvpZfiAM/Rio-Hamza.jpg)

Real photo of the underground river.
![rio-subterraneo-embaixo-do-rio-amazonas-1.jpg](https://steemitimages.com/DQmZWuLmqbox4fxP1RnGp5CSmfHAsAYTL3KD7fDLdh69r3s/rio-subterraneo-embaixo-do-rio-amazonas-1.jpg)