It is 42 km from Bursa on the Bursa-İzmir highway. In the Byzantine Period, Apollania ad Rhyndacum first became a part of the Diocese of Bitinia, then Nicomedia, and for a short time it was connected to the Dioceses of Kios.
After the Battle of Baleum (Koyunhisar) in 1302, the Ottomans came to Apollania for the first time by chasing the Kite Tekfuru who took refuge in this castle; However, during this siege, they reached the agreement due to the surrender of illegal tekfur, and they were contented with taking the island of Alyos only. By the conquest of this island, Apollania ad Rhyndacum was essentially dismissed from the steeped Lopadion castle at the exit gate of the lake.
Archaeological information about the ancient city can be listed as follows: The ruins begin from 3.7 kilometers south of the highway. Ancient roads are seen on the surface in the place known by the people as "Delik Taş". It is 1.7 meters wide in the west from two roads running parallel to each other. It is understood from the traces in the places where the wheels and horses were past, that it was used very much. Extensions of the roads are towards the Necropolis.
In the Necropolis Area, where sarcophagus boats cut from natural rocks and lids are widely seen, high monumental tombs measuring 8.5 x 8.5 meters were found at the edge of ancient roads. The same type of graves are also found on the shore of the lake. Documentary director Tekin Gün, who made research with the history of Gölyazı Ancient, has ruins of the Temple of Apollo on the island of Kız, located in the 50-meter-long shallow water overlooking the lake.
The outer castle is called "Stone Door" among the people. It was built to keep the narrowest part of the peninsula under control. A square prism bushing measuring 8.5 x 8.5 meters rises in the wall. In the construction of this sign, the stones of the open air theater in the city were used. The wall thickness of the wall reaches 5 meters in some places.
Customs and customs
There is Stork Festival held every year. Until the 20th century, Greeks and Greengrocers lived together. Until the 20th century, Greeks and Greengrocers lived together.