20-25 million years ago, the world began to cool and Africa began to crack. Today, the east side of the continent moves north while the west side moves south, and the fissure left on the plane is easily identified from outer space. In this seam have grown many beautiful lakes, among the deepest and largest in the world, including Lake Victoria.
Today, 20% of all the larger animals on earth are found in the Great Rift Valley making it the richest biomass for large animals on earth. The formation of the Rift is presumed to have been a major factor in the evolution of man.
Numerous African national parks and protected wildernesses are found on or near the Rift, and in East Africa you can actually see the spectacular cliffs and escarpments from many different places on the routine safari circuits.