In Kayseri's Develi district, Öksüt Castle — carved into the mountainside and believed to be at least 2,000 years old, possibly dating back to the Hittites — continues to stand strong.
The multi-storey rock-cut fortress, used in Roman and Seljuk eras, contains rooms, pools, water channels, animal shelters, dovecotes and worship areas, resembling an ancient city.