The Euphrates River flows in a general southeast direction from its origin at the confluence of the Murat Su and Kara Su Rivers in eastern Turkey to its terminal confluence with the Tigris River. The Shatt al-Arab, as the joint Tigris-Euphrates river is called, drains into the Persian Gulf.
The Euphrates and Tigris rivers follow relatively parallel courses through modern-day Syria and Iraq, forming an area between them that was historically known as Mesopotamia, meaning "between two rivers." The area is informally referred to as the Fertile Crescent. This area is widely thought among scholars to be one of the original sites of prehistoric civilization in the world, owing to the fertile land of the river plains.