Gulf of Gökova (Turkish: Gökova Körfezi) or Gulf of Kerme (Turkish: Kerme Körfezi; Greek: Κεραμεικός κόλπος; Latin: Ceramicus Sinus, lit. 'ceramic gulf'; or Gulf of Cos), is a long (100 km), narrow gulf of the Aegean Sea between Bodrum and Datça peninsulas in south-west Turkey.
Administratively, the Gulf of Gökova coastline includes portions of the districts of, clockwise, Bodrum, Milas, Muğla, Ula, Marmaris and Datça. The Greek island of Kos lies along the entry into the Gulf.
Knidos or Cnidus (/ˈnaɪdəs/; Ancient Greek: Κνίδος, Ancient: [knídos], Modern: [ˈkniðos], Knídos) was a Greek city in ancient Caria and part of the Dorian Hexapolis, in south-western Asia Minor, modern-day Turkey. It was situated on the Datça peninsula, which forms the southern side of the Sinus Ceramicus, now known as Gulf of Gökova. By the 4th century BC, Knidos was located at the site of modern Tekir, opposite Triopion Island. But earlier, it was probably at the site of modern Datça (at the half-way point of the peninsula).
It was built partly on the mainland and partly on the Island of Triopion or Cape Krio. The debate about it being an island or cape is caused by the fact that in ancient times it was connected to the mainland by a causeway and bridge. Today the connection is formed by a narrow sandy isthmus. By means of the causeway the channel between island and mainland was formed into two harbours, of which the larger, or southern, was further enclosed by two strongly built moles that are still in good part entire.