KEFALONIA IS THE LARGEST of the Ionian islands off the western seaboard of Greece, and has long been a popular destination for tourists, especially from northern Europe.
With its balmy Mediterranean climate, clear waters and rich historical background, few would question Kefalonia’s potential as a holiday destination. But apart from its obvious charm and featuring in the 2001 war film Captain Corelli’s Mandolin (starring Nicolas Cage), Kefalonia also presents a unique phenomenon that has intrigued scientists for nearly 200 years.
Here, at a discreet point on a peninsula, the sea flows into the land – and the water eventually reappears on the other side of the island.
I’ve been a cave-diver for 46 years, and had heard of this unusual phenomenon very early on in my diving career. The intriguing situation was recorded at Katavothres, on the headland near the capital Argostoli. As early as 1835 an Englishman called Stevenson documented the disappearing water, and subsequently a small water-wheel was constructed to operate a corn mill.
Scientists naturally took an interest in the unusual water flow, and in 1963 a strong dye was poured into the sink.
This experiment, carried out by Ioannis Petrocheilos and the Austrian hydrogeologists Maurin and Zölt, involved the use of 140kg of uranine, a very intensive green colour.
Amazingly, the green water was to reappear 14 days later near Sami on the eastern side of the island – more than nine miles away. Appearing first at the popular tourist venue Melissani Lake, it finally emerged from the flooded cave of Karavomilos, at a point slightly higher than sea level.
Diving in the lake.
Here again, a water-wheel was constructed. Today the structure is still evident and, while the wheel may no longer turn, it’s fascinating to see the brackish water running in force down the stone-lined channel to the sea a few metres away.
In effect, therefore, the water would appear to run uphill from one side of the island to the other!
Various theories have been formulated to explain this unique situation. While the most likely answer involves the mixing of fresh with sea water, and the complicated physics of water density, to an explorer the reality is that there is one exceptionally long cave system waiting to be uncovered there.
To date, numerous cave entrances have been located but few possess more than a few hundred metres of passages.
I had made a fleeting visit to Kefalonia back in 2003, and had been fortunate at that time to take some photographs in Melissani Lake Cave.
Archaeological discoveries made at this site mean that today dive access there is complicated, with permissions required from a government department in Athens. As such, divers need to be aware that the process is not quick or simple, and if filming or photography is envisaged, access will involve certain expense.