The Prince Islands ; officially just Adalar ("Islands"), are an archipelago off the coast of Istanbul, Turkey, in the Sea of Marmara. The islands constitute the Adalar district of Istanbul Province. The mayor of the Adalar district is Atilla Aytaç (CHP).
They consist of four larger islands, Büyükada ("Big Island") with an area of 5.46km2, Heybeliada ("Saddlebag Island") with an area of 2.4km2, Burgazada ("Fortress Island") with an area of 1.5km2, Kınalıada ("Henna Island") with an area of 1.3km2, and five much smaller ones, Sedef Adası ("Mother-of-Pearl Island") with an area of 0.157km2, Yassıada ("Flat Island") with an area of 0.05km2, Sivriada ("Sharp Island") with an area of 0.05km2, Kaşık Adası ("Spoon Island") with an area of 0.006km2, and Tavşan Adası ("Rabbit Island") with an area of 0.004km2.