Literally, almost a plain: an extensive area of low relief, dominated by convex-up (‘bulging’) hillslopes mantled by a continuous regolith, and by wide, shallow river valleys. Locally, monadnocks may occur. A peneplain is the end-product of a cycle of erosion, produced by the action of down-wearing over a long period of time, and it is the end-product of the Davisian cycle.