a deep, steep-sided, narrow river valley
cracks
a glen
There are more than one term for a deep narrow valley. Glens, canyons, ravines, fjords are terms you could use.
Those deep valleys are mainly in Wales, in the southwest of Britain.
deep narrow valleys and mountains
A narrow valley is a V-shaped valley, or river valley. A narrow valley has steep sloped sides that look like the letter V. They are formed by a strong stream.
Narrow deep valleys are sometimes called canyons. Or a small valley riginally worn away by running water and serving as a drainageway after prolonged heavy rains is called a Gully.
Such structure could be called a Canyon.
the river running through rock wear it down into deep valley with the steep sides what is it called
deep sea canyons
The Marianas Trench, and many other deep undersea valleys, can be found on the ocean floor.
mountains and water falls plateau deep river valleys vaconos