Knidos or Cnidus (; ) is an ancient settlement located in south-western Asia Minor, modern-day Turkey. It was an ancient Greek city of Caria, part of the Dorian Hexapolis. 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).