Geographically, a '''valley''' is an area of lower altitude with [[mountains]] or [[hills]] on either side. Most commonly, they are formed when a river cut down into bedrock, such as with the [[Grand Canyon]]. These have a V shape when seen in profile, and can have very steep slopes. When a [[glacier]] intrudes into one of these valleys, it causes the valley to widen and take on a U shape. Glacial valleys can be very wide, long and quite pronounced. | Geographically, a '''valley''' is an area of lower altitude with [[mountains]] or [[hills]] on either side. Most commonly, they are formed when a river cut down into bedrock, such as with the [[Grand Canyon]]. These have a V shape when seen in profile, and can have very steep slopes. When a [[glacier]] intrudes into one of these valleys, it causes the valley to widen and take on a U shape. Glacial valleys can be very wide, long and quite pronounced. |