Assyria is located in north Mesopotamia and spans four countries: In Syria it extends west to the Euphrates river; in Turkey it extends north to Harran, Edessa, Diyarbakir, and Lake Van; in Iran it extends east to Lake Urmi, and in Iraq it extends to about 100 miles south of Kirkuk. This is the Assyrian heartland, from which so much of the ancient Near East came to be controlled.Two great rivers run through Assyria, the Tigris and the Euhprates, and many lesser ones, the most important of which being the Upper Zab and Lower Zab, both tributaries to the Tigris. Strategically surrounding the Tigris and the two Zabs are the Assyrian cities of Nineveh, Ashur, Arbel, Nimrod and Arrapkha.