In the Ionian Sea lies grand Kefalonia. Much photographed , much talked about, much loved , by Greeks and Foreigners alike. This, the largest of the Ionian islands, with its sparkling azure waters, dazzling beaches and deep emerald green mountains, has been a popular holiday spot for decades Discover the World Famous beaches which you may have seen in posters or Movies. Go Trekking on the MountAinos the 'Black Mountain' The highest mountain in the Ionian.