Kefalonia is the largest of the lonian islands. Green rocks plunge suddenly into the deep blue waters. Picturesque villages and small beautiful towns highlighted by old mansions and "humble" farmhouses; a little further over, the ruins of some ancient city. Kefalonia has been justly called the island of contrasts: Roman, Venetian, and Byzantine ruins, side by side with famous beaches. The capital Argostoli is where the sea pours into spectacular swallow-holes and disappears endlessly into subterranean tunnels forming a rare geological phenomenon. The water reappears at Lake Melissani, an incredible semi-underground lake of clear turquoise and indigo water. Nearby is the Drogarati cave, a large stalagmitic cavern of rare beauty. To the north is the small village of Fiskardo, and its pretty harbour, that has escaped the earthquakes and retains the old style buildings.