All these lands are watered by important rivers: Nile, Jordan, Euphrates and Tigris. Together they cover some 400-500,000 square kilometers, and the region extends from the eastern shore of the Mediterranean Sea around the north of the Syrian Desert and through the Jazirah and Mesopotamia to the Persian Gulf. These areas are in present-day Egypt, Israel, West Bank, Gaza strip, and Lebanon and parts of Jordan, Syria, Iraq, south-eastern Turkey and south-western Iran. The population of the Nile River basin is about 70 million, the Jordan River basin about 20 million, and the Tigris and Euphrates basins about 30 million, giving the present-day Fertile Crescent a total population of around 120 million, or at least a quarter of the population of the Middle East.