First released in 1972, Werner Herzog's film is a tale of two trips, one of Spanish conquistadors trekking through the jungle in search of El Dorado, the other into an hallucinatory strangeness of the director's own making.
A severed head continues talking as it rolls to the ground; a boat sits lodged atop a tree; a hooded horse stands in perfect stillness on the edge of the jungle. And outdoing all else for pure nuttiness is Klaus Kinski in the title role, looking nothing like a Spaniard and every inch a mad-eyed Ubermensch. (Pauline Kael compared his frightening stare to Bette Davis.)
The actor allegedly tried to take over the film's troubled production in the same way that Aguirre seized control of the expedition, but he met his match in Herzog, who informed his star that he had a rifle and was quite prepared to use it. Somehow they got the film made, and 40 years later it remains an astonishing piece of work.