Yassıada, officially renamed Democracy and Freedom Island in 2013, is one of the Princes' Islands in the Sea of Marmara, to the southeast of Istanbul. In Byzantine times, it was known as Plati.
The island, which has an area of 183000 m2, is officially a neighbourhood of Adalar district of Istanbul Province, Turkey.
Wikipedia https://en.wikipedia.org/wiki/Yassıada
Coordinates 40°51'53.43" N 28°59'36.481" E