Which French cave is known in caving history as the first cave deeper than 1,000 meters?

Gouffre Berger was the first cave known to be explored deeper than 1,000 metres.

This cave lies on France’s Vercors Plateau, in the commune of Engins. Cavers discovered it on 24 May 1953, and subsequent expeditions pushed downward through shafts, passages, and underground rivers. It became the first cave to pass the celebrated 1,000-metre depth mark, earning the nickname “the first -1000.”

Gouffre Berger was also regarded as the world’s deepest cave from 1953 until 1964, when further exploration gave that distinction to the Pierre Saint Martin system. That history explains a common confusion: Pierre Saint Martin was a later depth-record holder, not the first cave below 1,000 metres.

The system is now recorded at about 1,271 metres deep and includes many kilometres of passages. Its water levels can rise rapidly after heavy rain, making descents hazardous. The name honours Joseph Berger, one of the cavers involved in its discovery.