Archaeologists in Turkey have identified massive structures below a Roman-era castle

https://www.npr.org/2023/09/01/ [login to see] /turkey-archaeology-zerzevan-castle-discoveries
As part of what was once ancient Mesopotamia, Turkey has long been fertile ground for archaeologists. It's home to significant sites that even predate Mesopotamia — UNESCO World Heritage Sites such as Gobekli Tepe, a Neolithic settlement believed to be more than 10,000 years old with what may be the world's oldest place of worship, and Catalhoyuk, a proto-city dating back some 9,000 years.

Now, more recent sites in the country's southeast are yielding finds that archaeologists say may change modern understanding of this part of the world's past, moving the footprint of pre-Roman activity in the area farther east than was previously believed.

Zerzevan Castle, the site of a Roman Empire military garrison, is providing what UNESCO calls "important information about the Roman soldiers, civilians' daily lives and the battles."