[bennyschmidt]

Think it was a different green area - the Fertile Crescent, not the Sahara. Eden would have been where modern day Kuwait is. As for ancient towns in Sahara, for a long time people wondered how the desert people lived in such a harsh area - but it turns out they've just been there since it was lush. They didn't move to the desert and learn how to survive there, they're just what's left of those populations from the Sahara, and adapted to the changing conditions.