Valley
| Basic: |
| A valley is a type of the union of { valleys, shorelines }, natural inanimate thing, and depression. |
| Documentation: |
| Comment: A specialization of LandTopographicalFeature, CavityWithWalls, and InanimateObject-Natural . Each instance of #$Valley is of significantly lower altitude than the area surrounding it. A #$Valley is distinguished from a Basin by having sharper sides, and typically has #$Mountains (or smaller elevations) surrounding it. |
| Structure: |
| Some valley is in every group of valleys and every mountain range. Many valleys are in every mountain range. |
| Every branching junction that is a part of a valley is a physical part of some valley. |
| Size: |
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| Miscellaneous: |
| Every geographical region that is in some valley is in some valley. Every valley is between 0 and 100,000,000 years old. |