Bathyscaphe Trieste
On 23 January 1960, she reached the ocean floor in the Challenger Deep (the deepest southern part of the Mariana Trench), carrying Jacques Piccard and Don Walsh. This was the first time a vessel, manned or unmanned, had reached the deepest known point of the Earth's oceans. The onboard systems indicated a depth of , although this was revised later to ; fairly recently, more accurate measurements have found Challenger Deep to be between and deep.
Gouffre Jean-Bernard
Gouffre Jean-Bernard or Réseau Jean Bernard, sometimes known simply as Jean Bernard, is one of the deepest caves known in the world. It is 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 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.