These caves " are part of an underground river , and the 5,000 meters that have been exposed are fascinating. From the entrance, skillful, whistling gondoliers steer small boats through narrow passageways, around beautiful formations of stalagmites and stalactites, their colors created by rain water penetrating the calcium carbonate in the rock. The caves have served as places of worship in Paleolithic and Neolithic times; they are thought by many to be connected to the Underworld."
