Knidos or Cnidus, located in southwestern Asia Minor, modern-day Turkey, is an ancient Greek city of Caria, part of the Dorian Hexapolis.

It is situated on the Datça peninsula, which forms the southern side of the Sinus Ceramicus, now known as Gulf of Gökova.

By the 4th century BCE, Knidos is 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 is 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 harbors, of which the larger, or southern, was further enclosed by two strongly built moles that are still in good part entire.The extreme length of the city is little less than a mile, and the whole intramural area is still thickly strewn with architectural remains.

The walls, both of the island and on the mainland, can be traced throughout their whole circuit; and in many places, especially round the acropolis, at the northeast corner of the city, they are remarkably perfect.Knidos is a city of high antiquity and as a Hellenic city probably of Lacedaemonian colonization.

Along with Halicarnassus (present day Bodrum, Turkey) and Kos, and the Rhodian cities of Lindos, Kamiros and Ialyssos it forms the Dorian Hexapolis, which holds its confederate assemblies on the Triopian headland, and there celebrates games in honor of Apollo, Poseidon and the nymphs.They ultimately submit to Cyrus, and from the battle of Eurymedon (469 or 466 BCE) to the latter part of the Peloponnesian War they are subject to Athens.