Hasankeyf
The waters of the Tigris River gave rise to the first settlements of the Fertile Crescent in Anatolia and Mesopotamia—the cradle of civilization. The ancient city of Hasankeyf, built on and around the banks of the river in southeastern Turkey, may be one of the oldest continuously inhabited settlements in the world, spanning some 10,000 years. Hasankeyf and its surrounding limestone cliffs are home to thousands of human-made caves, 300 medieval monuments and a unique canyon ecosystem—all combining to create a beguiling open-air museum.
More than 20 cultures have left their mark at Hasankeyf. The first settlers probably lived along the Tigris in caves carved into the rock cliffs. (The ancient Assyrian name for the place was Castrum Kefa, meaning "castle of the rock.") The Romans built a fortress there circa A.D. 300 to patrol their empire's eastern border with Persia and monitor the transport of crops and livestock. In the fifth century A.D., the city became the Byzantine bishopric of Cephe; it was conquered in A.D. 640 by the Arabs, who called it Hisn Kayfa, or "rock fortress." Hasankeyf would next be successively ruled by the Turkish Artukid dynasty, the Ayyubids (a clan of Kurdish chieftains) and the Mongols, who conquered the region in 1260.
Hasankeyf emerged as an important commercial center along the Silk Road during the early Middle Ages. Marco Polo likely passed over its once-majestic stone, brick and wooden bridge, built around 1116 (only two massive stone piers and one arch remain). In 1515, the city was absorbed into the Ottoman Empire and has since remained a part of modern Turkey.
Among the site's most important structures are the ruins of the 12th-century palace of the Artukid kings; the El Rizk Mosque, built in 1409 by the Ayyubid sultan Suleiman; and the 15th-century cylindrical Tomb of Zeynel Bey (the eldest son of Uzun Hasan, who ruled over the region for 25 years). The tomb is decorated with glazed blue and turquoise bricks in geometric patterns that suggest a significant artistic link between Central Asia and Anatolia.
Unfortunately, the city, along with the archaeological artifacts still buried beneath it, is slated to become a sunken treasure. The massive hydroelectric Ilisu Dam is expected to be completed in 2013. The reservoir created by the dam will inundate the site's caves and flood most of its structures.