Marmara Island (Turkish: Marmara Adası; Greek: Προκόννησος Proconnesus) is a Turkish island in the Sea of Marmara. With an area of 117.8 kmÂ² (45.5 sq mi) it is the largest island in the Sea of Marmara and is the second largest island of Turkey after Gökçeada (older name in Turkish: İmroz; Greek: Ίμβρος Imvros). It is the center of Marmara district in Balıkesir Province. Transportation is possible from Istanbul by ship and ferry, and by motorboat from Tekirdağ and Erdek. Marmara island is full of historical treasures which increase its attractiveness. The town of "Mermer Plaj"/Marble Beach takes its name from the marble for which the town is famous and which gives the island and the sea their name.