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