Cliff

A cliff is a steep or vertical face of rock, formed by the actions of erosion, weathering, and tectonic uplift that expose resistant rock. Cliffs can occur along coastlines, in river valleys, or on plateaus. Coastal sea cliffs develop where waves attack the base of a rock mass, undercutting it and causing rockfall that yields a near-vertical face. Inland cliffs form where river incision or faulting creates an abrupt drop in elevation, and where rock layers differ in resistance. Glaciation can also abrade rock faces, leaving escarpments.

Cliffs commonly display ledges and overhangs; caves and arches may form through differential erosion, and talus or scree often accumulates at the base. The rock type, bedding, joints, and tectonic history determine a cliff’s shape and stability. Weathering, frost action, and rain contribute to gradual retreat and occasional sudden rockfalls.

Ecology and human use: Cliff habitats support specialized plants and nesting seabirds and raptors. Cliffs pose hazards to hikers and property; rockfalls can damage infrastructure. Many cliffs are protected as part of national parks or protected landscapes, and access may be regulated to reduce risk.

Notable examples: The Cliffs of Dover in England, the Cliffs of Moher in Ireland, and the Preikestolen (Pulpit Rock) in Norway are well-known cliff formations.