Crags

Crags are steep, rugged rock faces or cliffs that rise abruptly from the surrounding terrain. The term is used across geology, geography, and outdoor recreation to describe natural rock outcrops that stand in relief against their surroundings. Crags occur in upland areas, within river valleys, and along coastlines where wave action has undercut softer rock.

Formation and types: Crags form through a combination of tectonic uplift, surficial weathering, and differential erosion. The rock type strongly influences their appearance: hard, resistant rocks such as granite, quartzite, or basalt may produce sheer, vertical faces, while softer sedimentary rocks like limestone or sandstone often create stepped cliffs with ledges and gullies. Coastal crags are carved by persistent wave action; inland crags may be shaped by rivers or glaciation.

Morphology and ecology: Common features include ledges, cracks, fissures, chimneys, and overhangs. These features create microhabitats for lichens, mosses, and other vegetation on shaded surfaces, and can support invertebrates, bats, and nesting birds in crevices or ledges.

Human use and management: Crags are popular for recreational climbing, scrambling, and sightseeing. Access and use are often regulated to protect wildlife habitats, reduce erosion, and ensure safety. In some regions, former quarries or natural outcrops are managed as protected areas or climbing venues.