And this cataract, which is basically jagged cliffs and boulders and rapids, is really going to form the starting point for Egyptian society. Now the Nile is generally divided along that 750 mile strip in Egyptian civilization into two sectors. You have what's called the upper Nile and the upper Nile which is highlighted right there is actually in the lower portion of Egypt. But that's going to be characterized really by a thin strip of fertile soil surrounding that river. And as we get into the lower Nile, which is in the upper part, that's going to be characterized by a delta which is very lush and wider and larger because it's flowing into the Mediterranean Sea. So there are going to be different parts of the Nile. But starting around 5,000 BCE, we're going to see kind of farming villages pop up along the 750 strip of the Nile River.