canyon

A canyon (fluvial landform) as defined by the Getty Art and Architecture Thesaurus: Deep, steep-sided land depressions, often having a river at the bottom; common to arid and semi-arid areas. Distinct from "valleys (landforms)," which tend to have a flattish landscape rather than high, precipitous slopes. Distinct from "gorges (landforms)," which tend to be smaller, narrower, and more rocky.