The Nile river is famous basically for three things: it is one of the longest in the world, it has an uncannily fertile valley surrounding it in the middle of the desert, and it reminds us of the fabulously rich Egyptian culture.
But the Nile was not only the cornerstone of the ancient Egyptian civilisation: it apparently is an anomaly because it creates a kind of ecosystem around it that has apparently nothing to do with the Sahara, with the dunes and sand that surrounds it.
So, this apparent discrepancy called the attention of more than one scientists, and research was conducted in order to know more about the river and the region. Among other things, scientists used infra-red (IR) and ultra-violet (UV) cameras deployed in satellites, as well as radar imaging to study the surface of the Saharan desert, and what they found was exceedingly surprising: the Nile is the key to other secrets.
What is interesting about the Sahara is not the surface, but what lies approximately ten metres below the sand: scientists found that there is a rock and soil bed that shows erosion patterns that have nothing to do with a sandy desert. In fact, what they found is that apparently, ten thousand years ago there was a severe climate change in the area, with serious desertification. The ecosystem in northern Africa up to then was similar to that found around the Nile valley, and giraffes reached as far as the Mediterranean coast.
Those sub-surface images show the typical forms associated with flowing water, canals, islands and so on. Biblical chronicles as well as what has been documented from ancient cultures also prove that the fauna was different and the region was indeed much more fertile.
What happened is still unknown, but what is sure is that the Nile is the key to all kinds of secrets and treasures.