The city of Kane, on one of the Arginousai islands and close to the naval battle of 406 BC, may have been located on what is now a peninsula of the mainland, the channel having silted up at some point before the 16th century - http://news.nationalgeographic.com/2015/11/151119-lost-island-aegean-kane-sparta-athens-archaeology/
Good to know: thanks, Duncan. This is consistent with the eastern and western coasts of the Aegean generally silting up and the land expanding, while parts of the northern coast seem to be flooding or eroding (Herodotus' plain and town of Doriscus, for example, seem to be largely underwater).