The Natural Interactive Walking project (NIW) will proceed from the hypothesis that walking, by enabling rich interactions with floor surfaces, consistently conveys enactive information that manifests itself predominantly through haptic and auditory cues. Vision will be regarded as playing an integrative role linking locomotion to obstacle avoidance, navigation, balance, and the understanding of details occurring at ground level. The ecological information we obtain from interaction with ground surfaces allows us to navigate and orient during everyday tasks in unfamiliar environments, by means of the invariant ecological meaning that we have learned through prior experience with walking tasks.