The lowering and smoothing of a landscape by cryogenic processes. ‘To deny the fairly widespread existence of features commonly called cryoplanation benches, terraces, and pediments would be foolish: to claim that there is anything approaching an adequate explanation of their origin(s) would be even more foolish…there is little to say about cryoplanation other than the concept needs to be challenged directly’ (Thorn and Hall (2002) PPG 26, 4).