Gorges and Canyons

Canyons, gorges, ravines and slot canyons cut by concentrated river or floodwater erosion into narrow, steep-walled channels, following the fluvial canyon class of standard geomorphology. Includes major river canyons (Grand Canyon, Gorges de l'Ardeche), narrow slot canyons cut into soft sandstone (Antelope Canyon), and named gorges and ravines worldwide (Rugova Canyon, Elora Gorge). Belongs here: any channel-like feature whose defining shape is markedly steep, narrow walls cut by concentrated water erosion. Does not belong here: a broad, open valley without steep confining walls (Valleys), or a karst passage shaped by dissolution rather than mechanical river erosion (Karst Caves and Sinkholes).