There are two versions, as far as the name of the island is concerned. According to the first one, Koufonisia or Koufonissi, was the ancient name of the gulf which is between Koufonisia and Glaronisi. As a matter of fact, the full name was “Koufos Limin”, which means lee port, where ships can anchor.
According to the second version, this name was chosen because of the large number of caves and sediments without boisterous rocks that are found on the island. Anthony Miliarakis, in contrast with these two theories, wrote in his book in 1920 that Pano Koufonisi was known as “Fakousa” and Kato Koufonisi as “Pino”.