Book excerpt: The study of hillslopes is a central element of geomorphology, and has been the cause of many of the major methodological disputes in the subject. This book describes the present state of knowledge of hillslope form, the results of measurements of hillslope form and points to unresolved problems in the understanding of it. The book deals with observed variations in hillslope form across the surface of the earth and concludes by examining the influence of man on hillslopes and assessing the contribution that the understanding of natural hillslopes may make to the management of man-made inclines.