Canyons (synonyms: gorges, ravines; example toponyms: Granview Canyon, Bryant’s Cleft) are deep chasms between cliffs or escarpments formed by river erosion. Fictional canyons may form impassable or nearly impassable barriers with a few key traversable locations. There may be steep paths or stairs leading from the bottom to the top of the cliffsides. These paths may be secret or hidden. Canyons may be home to towns or cities situated within the gorge, on either side of the cleft, or hanging from the cliffsides themselves. There may be perilous bridges or entire bridge systems spanning the two sides. Canyons are formed via river erosion but the river may have dried up years ago and may no longer exist. Alternatively, canyons may be sites of extreme flooding during heavy storms.

Canyons are often found in arid areas with lots of limestone.