Diyarbakir

On a bluff above the Tigris River, the ancient city of Diyarbakir, one of the oldest cities in the northernmost region of Mesopotamia (the area between the Tigris and Euphrates rivers) is encircled by a 5.5-km (3-mi) stretch of thick, impregnable black-basalt walls. Inside those walls lie twisting alleyways, old stone homes, mosques, and a lively bazaar. The city's long history has meant it's seen quite a succession of rulers, from the Assyrians to the Urartians and Romans, and finally the Ottomans, who took control of the city in 1515. Diyarbakir has been an important regional commercial and cultural center for centuries, and there are some wonderful old houses, mosques, and churches in the cobblestone lanes of the old town.