Jean-François Pernette

Jean-François Pernette, considered to be one of the world's greatest speleologists, explores a cave in the Pyrenees. Pyrenees Mountains, France

The caves in limestone plateau formations that Jean-François Pernette has been exploring frequently contain magnificent mineral formations.

The cave formations are natural artworks of extraordinary beauty.

Inside the Avenir water sinkhole, flash floods are a very real danger to Pernette's team. Perte de l'Avenir, Patagonia.

The powerful forces of nature have carved the spectacular scenery from marble. Diego de Almagro island, Patagonia, Chile

Pernette and his colleagues have dubbed the jagged, polished and rain-pitted rock surface of Madre de Dios, "glaciers de marbre", marble glaciers. Patagonia, Chile

The wind, called the "undisputed lord of Patagonia", reaches velocities of 200km an hour. Diego de Almagro island, Chile

A member of the team rigs the ropes to explore a shaft 70 metres deep. Abraham Canyon, Patagonia.

The terrain on the islands is so difficult that a boat has to serve as base camp for the expedition. Patagonia, Chile

The team takes advantage of a rare spell of fine weather to explore the Pacific coast of Madre de Dios island. Gale-force winds and storms make such outings impossible for most of the year. Patagonia, Chile