Iznik Hacı Özbek Mosque
The building has the distinction of being the first Ottoman Mosque whose inscription has survived to the present day. It is very important as it is the first Ottoman structure whose history is known with its inscription. Another important feature is that it is considered the first example of the central domed building type built in Western Anatolia during the Early Ottoman period.

According to its original inscription, which is currently on the western wall of the mosque, it was built by Hacı Özbek, son of Muhammad, in 1332-1333. It has a square planned space. It is covered with a tile-covered dome resting on a twelve-cornered drum. It was originally a small mosque with a narthex with two columns in front. The current state of the mosque emerged due to the arrangements made in the Iznik road texture in 1959. During the arrangements, the narthex on the western façade was demolished and a new three-span narthex was built in its place to the north of the main space.

As a result of the restoration works started in October 2000, the roof cover, walls, windows and doors were repaired.