In pictures: Hidden treasures of Hasankeyf

Doubts are hanging over Turkey's plans to build a controversial dam in Ilisu, after the main UK construction firm pulled out of the project. Opponents want the dam abandoned - partly to save the treasures of the ancient city of Hasankeyf, which will be lost forever under the waters if the dam goes ahead.

Hasankeyf is situated beside the River Tigris

Its magnificent rock caves have labyrinths of stairs and passageways

Ancient remains can be seen around the city

The city was an important economic and cultural centre, because of its strategic location

A 12th century stone bridge crossing the Tigris is among the sights

Kurds say that Hasankeyf is the last remnant of Kurdish identity

Thousands of people would have to leave if the dam went ahead