The ancient region of Southwest Asia known as Mesopotamia, means literally ""between rivers" : the Tigris and Euphrates, that have their headwaters in the mountains of Asia Minor and ultimately merge as they flow into the Persian Gulf, nearly 1,000 miles to the east.  This fertile land, tilled for 10,000 years, has been called the cradle of civilization. .  Here, about 5,000 years ago, mankind attempted to develop a system of writing, and built the world's first major cities.