From atlasobscura.com:
"QSHLA KOYA, ALSO KNOWN AS Qishla Koysinjaq, is a fortress located on a hillock in the central quarter of Koya, a lovely town in the Northeast of Iraq.
"Although there is a lack of consensus among scholars, it’s generally believed that Qshla Koya was constructed between 1869 and 1872, under the aegis of the Ottoman Empire. The purpose of the structure was unmistakably military, housing troops and providing a strategic vantage point to monitor the surrounding area.
"The enormous courtyard once used for military activities has been transformed into a garden. Enclosing the courtyard are fortified walls with round bastions at the corners. Along the walls that demarcate the perimeter of Qshla Koya are wide wall walks, where underneath, visitors can find the buttery, barracks, and stables. The dominant structure, however, is the two-story main building where the front gate is located. Two symmetrical sets of stairs lead to the upper floor of this building.
"Today, although Qshla Koya has lost its strategic military value, it has gained cultural standing. Now, the main building houses the Koya Civilization Museum. The museum was founded in 2003 and items on display include tablets with astounding samples of cuneiform script from 2000 BC; there is also pottery dating back to 6000 BC, ancient jars, coins, jewels, and a wealth of documents from the Ottoman period."
The Koya Fortress is enjoyed as a spot to visit by locals, and it was pleasant to encounter this family as we strolled the ramparts.