One of the high-water marks in survival cinema, Nicholas Roeg's stunning 1971 film Walkabout perfectly illustrates the clash between civilized society and Mother Nature. When two Australian schoolchildren are abandoned in the outback by their insane father, they meet up with an Aboriginal boy and try to adapt to life without any of the modern conveniences that they depend on. It's stunning, lyrical and oftentimes deeply harrowing. Walkabout is out on DVD from the Criterion Collection, so pick that sucker up.