The Diros Cave was discovered by accident at the end of the 19th century. It took another fifty years until a pair of speleologists, Anna and Ioannis Petrocheilos, begun a systematic research that led to the opening of the cave to visitors. An underground river whose waters are mixed with those of the sea is responsible for its less salted water which gave the name to the cave: Vlychada or Glyfada (sweet water).