İmralı is a small Turkish prison island in the south of the Sea of Marmara, west of the Armutlu-Bozburun peninsula within Bursa Province. It measures 8 kilometres (5 miles) in the north–south direction with a width of 3 kilometres (2 miles), and has an area of 9.98 square kilometres (3.85 sq mi). The highest peak is Türk Tepesi at an altitude of 217 metres (712 feet) above sea level. It is prohibited to fly over it or fish near its shores. History. In antiquity, it was a member of the Delian League since it appears in tribute records of Athens between 434/3 and 418/7 BCE.
https://en.wikipedia.org/wiki/%C4%B0mral%C4%B1