Werner Herzog

German filmmaker Werner Herzog was one of the few people permitted to enter a cave in France containing the oldest recorded cave paintings. What he saw — and what he imagined — is the subject of a new documentary, The Cave of Forgotten Dreams.

The 71-year-old German filmmaker made daring movies in the 1970s that pushed viewers into unsettling mental spaces. The tremendous boxed set Herzog: The Collection highlights his authentic style.

Les Blank is one of the filmmakers who directed the documentary "Burden of Dreams," which will be playing at the International House in Philadelphia. The documentary is about the making of Werner Herzog's fictional film "Fitzcarraldo," which chronicles an Irishman trying to build an opera house in the Amazonian jungle. This interview originally aired on Michael Goodwin's radio program about film on Pacifica Radio Station KPFA in Berkeley. (INTERVIEW BY MICHAEL GOODWIN)