Werner Herzog's Cave Painting Documentary: Werner Herzog's Cave Painting Documentary

Happened at Chauvet Cave in southern France. A friend is an expert on this stuff. He can track the artists by the shape of their hands, missing fingers, and so on.

The cave, discovered in 1994, is home to hundreds of pristine artworks. Over 30,000 years old, they are the oldest known pictures created by humans and show at least 13 different species of animals, including horses, cattle, lions and bears.

In the spring of 2010, Herzog was given a unique opportunity to film inside the cave. He and his team were only allowed access for a period of a few days, and were only able to use battery-powered equipment. High levels of radon gas and carbon dioxide in the cave meant they could only stay inside for a few hours at a time.

The director opted to make the film in 3D -- the first time he has used the technology -- to do justice to the cave paintings, which use the contours of the rock for dramatic effect. "I knew immediately that it was imperative to shoot in 3D," he says. The result is a visually stunning documentary that transports the viewer into the cavern and captures the artwork in all its glory.

Der Speigel's interview with Herzog here.