You can see it clearly on any physical map. The Dry World is that only region colored in the khaki mocha tone of the Sahara sands. This region, then, is defined loosely by the Sahara desert, the Atlas Mountains in the west, and the Nile River in the east.
The Dry World is dominated by just two languages; the related languages of Arabic and Berber.
Perhaps our greatest story is how we populated the world, a question which begins with how early humans, and also early hominins, left the African continent. The likely migration route is through North Africa. Anthropologists believe our ancestors have been migrating out of Africa for as long as 1.8 million years. This lends to the region's mystery as an ancient place, and a connection between the oldest civilizations.