The concept of the geomorphic cycle is a foundational principle in geology and geomorphology, but the topographic evolution of a single landscape from inception to senescence has not been demonstrated in nature. The Cooloola Sand Mass (CSM) in eastern Australia preserves dune landforms from initial formation to the achievement of maturity (a morphologic steady-state) and its topographic evolution parallels that of physical based models of dry unconsolidated sand. Our field based measurements and forward numerical models demonstrate that this evolution is caused by nonlinear sediment transport governed by hillslope thresholds. Our findings confirm that physical models of landscape evolution are applicable at the landscape scale. We also propose that the distribution of curvature (C) of a landform, and its associated standard deviation (σC) represents a landscape’s potential for change. Once σC is normalised, it can be used to measure and define the evolution of topography and is an essential morphometric tool for understanding landscapes.