What is the Rio Hamza?

An aerial view ... the Amazon river.

It is name of an underground river that flows 4 Kilometres below the Amazon.
THE Amazon basin covers more than 7 million square kilometres in South America and is one of the biggest and most impressive river systems in the world. But it turns out that - until now - we have only known half the story.
Brazilian scientists have found a new river in the basin - around four kilometres underneath the Amazon River. The Rio Hamza, named after the head of the team of researchers who found the groundwater flow, appears to be as long as the Amazon but up to hundreds of times wider.