Gaziantep Castle Gaziantep Castle is built on a hill at the center of Gaziantep in Turkey. Hittite Empire initially used it as an observation point before the Roman Empire turned it into its main castle and expanded and renovated it even more beneath Emperor Justinianus between 527 AD to 565 AD. The walls are made from stone, span 1200 meters in circumference, and consist of 12 towers that house living quarters for soldiers along with various other chambers such as stables, prison cells, storerooms for treasure troves or barracks for troops. The castle took its final shape in 2000 and has been renovated many times. It is now the Gaziantep Defence and Heroism Panoramic Museum, which shows a documentary about the defence of the city against French forces.