Gouffre Jean-Bernard 1.66

Gouffre Jean-Bernard or Réseau Jean Bernard, sometimes known simply as Jean Bernard, is one of the deepest known caves in the world. It is found in the Alps, in Samoëns, France. The first entrance to the cave was found by the French caving group Groupe Vulcain in 1963. More entrances have been found over the years since, and currently at least thirteen are known. The highest entrance, known as C37, is at 2,274 m above sea level. The cave is named after Jean Dupont and Bernard Raffy, two Groupe Vulcain members who died in 1963 in an unrelated expedition.ExplorationExploration of the cave began shortly after discovery in 1963. By 1969, the cave had been explored to a depth of 623m below the level of the highest entry point. At that point, further exploration was blocked by a water-filled tunnel.Subsequently, another entrance was discovered that had passages that bypassed the flooded tunnel. The cave was explored to 938m before again becoming blocked, this time by fallen rocks. In 1976, these rocks were removed, allowing explorers to descend to 1298m; at the time, that made it the second-deepest known cave, although it has since been surpassed.More recent explorations have found it to be approximately 1602m deep, making it the sixth-deepest cave in the world.