The structure collapsed as a result of lightning stroke and built by Alaeddin Keyqubad I in the first half of the 13 th century, was reconstructed by Suleiman the Magnificent by using old materials. The building known as Alaeddin or Kale (Castle) or Orta Hisar (Middle Fortress) Mosque, is dated to 16 th century by its plan, structure type, shape of dome and arch and stone and wood craftsmenship.
The narthex, which is hemisphere dome on the top, divided into three by diagonal arches with a square space and covered with three small domes, forms the main spot of the mosque. Domes are laid with brick but its walls are from partly brick and square stones. A minaret was added to northwestern corner of the harem and a vaulted cistern was constructed opposite of the northeastern corner. Next to the cistern, there is a covered place for performing ablution.