A steep rock face, usually facing the sea; see Lee et al. (2001) Geomorph. 40, 3–4 on probabilistic models for different cliffs. While an active cliff is still subject to the forces of marine erosion, an abandoned cliff is protected from wave attack by a wave-cut platform or by a barrier beach. As the abandoned cliff is exposed to subaerial denudation it becomes less steep, and its upper edge more indented. See Hutchinson (1984) DTIC ADA144040.