The Princes' Islands, Istanbul Islands or Red Islands are the archipelago, known as the Islands, located in the northeastern part of the Sea of Marmara, off the southern coast of the Anatolian Side of Istanbul. It consists of 9 large and small islands and two cliffs close to the shore.

At the same time, a district of Istanbul has settlements in five of the regions (Büyukada, Heybeliada, Burgazada, Kinaltada and Sedefadasi). On the other hand, there is no permanent and practical settlement in Sivriada, Yassiada, Kask Island and Tavgan Island.