41°12′58″N 30°15′40″E / 41.21611°N 30.26111°E
Kefken Island (Turkish: Kefken Adası), lies off the Black Sea coast of Turkey, a short boat ride from the mainland village of Cebeci in the Kandıra district of Kocaeli Province.
It has an area of 21 hectares, and is about four times as long as it is broad.