Does Niksar have a castle?

Niksar, historically known as Neocaesarea (Νεοκαισάρεια), is a city in Tokat Province, Turkey. It was settled by many empires, being once the capital city of the province. Niksar is known as "Çukurova of North-Anatolia" due to its production of many kinds of fruits and vegetables. On May 2, 2018, Niksar was included in the World Heritage tentative list

Yes, Niksar has a historic castle overlooking the old city. It is used during Roman, Byzantium and Ottoman times.