Draft:Diros cave

The Glyfada Cave (or Vlyhada) Dirou is a visitable cave located on the western coast of Laconian Manis, in the Bay of Dirou, Eastern Mani.

Background
Its existence was known to the locals from around 1900. In 1949, the founders of the Hellenic Speleological Society, Yannis and Anna Petrocheilou, began to systematically explore it. Until 1960, 1,600 meters had been explored and mapped, while today the known length of the cave exceeds 15 kilometers. In 1970 the first underwater exploration took place. At one point of the cave, the depth reaches about 100 meters.

The cave began to form hundreds of thousands of years ago. The stalactites and stalagmites that are now underwater were formed when the sea level was much lower than it is today. The water inside is brackish and very hard. Its temperature is around 14°C, while the air varies from 16 to 19°C.

Its natural entrance has a diameter of only half a meter and is very close to the surface of the sea. In earlier times the cave had other entrances which were gradually closed.

Inside the cave have been found fossilized bones of panther, hyena, lion, deer, ferret and the largest concentration of hippo bones in Europe. Near its natural entrance, ceramics have been found that indicate human presence.

220 m. east of Glyfada is the "Alepotrypa" Cave. This Cave contains petroglyphs.

Navigation history
The Glyfada Cave was discovered in 1923 by residents of the region. The first systematic description was made in 1949 by the founders of Greek speleology, the couple Ioannis Petrocheilos and Anna Petrocheilou. By the time Ioannis Petrocheilos died in 1960, 1,600 m had been explored, of which 1,300 m were waterways. The exploration was continued by the Greek speleological society and since 1961 a part has been open as a show cave. By 1966, a further 1,500 m of waterways could be explored; A diving expedition on the first Siphon was unsuccessful. In 1970/71, 300 m of underwater passages were explored by Greek and American cave divers. Further advances:
 * 1989: 5,300 m (giant cave status achieved)
 * 1992: 6,200 m
 * 2000: 10,606 m
 * 2005: 15,400 m (longest cave system in Greece)

The Swiss cave diver Jean-Jacques Bolanz reached a depth of 78 m and found stalactites down to a depth of 71 m. The Glyfada is the fifth deepest underwater cave in Greece.