A "crag" is climbing slang for an outdoor climbing area — a cliff, rock face, or grouping of boulders where climbers go to climb on natural rock. The word originally meant a steep rugged rock or cliff, and climbers have adopted it as the catch-all term for any outdoor venue.
Crags vary enormously. Some are single-pitch sport crags with bolted routes a few minutes from the car park. Others are multi-pitch trad crags requiring full racks of removable protection. Some are bouldering areas with no rope climbing at all. The character of a crag is shaped by its rock type (limestone, granite, sandstone, gritstone), its grades, its access, and its local climbing culture.
Guidebooks and online databases catalogue crags by region, listing routes, grades, approaches, and seasonal information. Popular crags can become busy on weekends, especially those close to major cities or with concentrations of moderate-grade routes. Respecting the crag — leaving no trace, parking responsibly, and following local ethics — is essential to keep climbing access open.