What is hanging valley?
A river valley is V shaped and is fed by other streams coming in from the sides which have their own valleys. During glaciation, a glacier moves down the river valley, carving a U shaped valley and widening and deepening the existing valley. The valleys of the feeder streams are cut off. When the glacier retreats, it leaves the glacial valley with steep sides and the feeder valleys enter near the top. Water coming down these cut off valleys often falls into the glacial valley as a waterfall. These cut off valleys that hang high on the sides of the glacial valleys are the hanging valleys.
