Erdek is a town and district of Balıkesir Province in the Marmara region of Turkey. The population was 34,000 in 2010. Located on the Kapıdağ Peninsula, on the north coast of the Gulf of Erdek at the south of the Sea of Marmara, Erdek is a popular domestic holiday destination with several hotels dating back to the 1960s. The surrounding area has a rugged geology and topography with evergreen wooded areas and large olive groves. It is dominated by Mt Dindymus.
In the summer ferries travel from Erdek to Avşa Adası, one of the Marmara Islands in the Sea of Marmara. The harbour overlooks tiny Zeytinlik island where there is a research station devoted to olives.
Wikipedia https://en.wikipedia.org/wiki/Erdek
Coordinate 40°23'50.767" N 27°47'27.554" E