Heybeliada or Heybeli Ada (Greek: Χάλκη, Halki) is the second largest of the Prince Islands in the Sea of Marmara, near Istanbul. It is officially a neighborhood in the Adalar district of Istanbul, Turkey. To the right of the jetty lies the town with its bars and cafés, a hotel that stays open all year round, and many lovely Ottoman era wooden houses. TCG Heybeliada, the lead ship of the twelve Milgem class corvettes (first eight) and frigates (last four) that are being built for the Turkish Navy, is named after the island.