7. The Great Euphrates
The Euphrates (Arabic: الفرات: al-Furāt, Turkish: Fırat) is the longest and historically one of the most important rivers in the world.
Together with the Tigris, it is one of the two defining rivers of Mesopotamia.
The river – originating in eastern Anatolia in Turkey – flows through Syria and Iraq to join the Tigris in the Shatt al-Arab, which empties into the Persian Gulf.
Many important ancient cities were located on or near the riverside, including Mari (illustrated left), Sippar, Ur and Eridu. Today from damming the river, it is at great risk. See it while you can.
Image via Wikipedia