Siege of Singara
360 CE.
Shown on the map at 36.322°, 41.864°.
The siege of Singara took place in 360, when the Sasanian Empire, under Shapur II, besieged the town of Singara, held by the Roman Empire. The Sasanians successfully captured the town from the Romans.
Text from the Wikipedia article Siege of Singara (360), licensed CC BY-SA 4.0.