This is

the courtyard of a citadel. “The dark basalt mass of the citadel (3rd century, rebuilt in 13th and 15th century) rises in the center of the town. With its warlike sight, the lava blocks and the 19 towers  on the rampart is one of the most spectacular example of turkish architecture of the middle age. It features of a sophisticated defence system, including a 30 m long Barbakane between a double outside gate and a watch tower.” (Via Michelin)