Castellana caves (Castellana Grotte), Apulia, Italy, Europe

Famous Melissani Lake, Kefalonia island, Greek Islands, Greece

Tourists admiring the cave during a boat trip on the crystal waters of Melissani Lake, Kefalonia, Ionian Islands, Greek Islands, Greece, Europe

Castellana caves (Castellana Grotte), Apulia, Italy, Europe

Tourist boats in the crystalline blue waters of Melissani Lake cave, Kefalonia, Ionian Islands, Greek Islands, Greece, Europe

Tourists enjoying a boat trip into the cave at famous Melissani Lake, Kefalonia, Ionian Islands, Greek Islands, Greece, Europe

Cephalonia, tourists driving in boats in front of Melissani cave in Sami, Ionian Islands, Greece

Cephalonia, tourists driving in boats in front of Melissani cave in Sami, Ionian Islands, Greece

Melissani lake and cave in Sami, Cephalonia, Ionian Islands, Greece