#valley__vale  a long depression in the surface of the land that usually contains a river
  supertype:  #natural_depression__naturaldepression__depression  a sunken or depressed geological formation
  instance:  #San_Joaquin_Valley  #Shenandoah_Valley
  subtype:  #dale  (British) an open river valley (in a hilly area)
  subtype:  #glen  (Scottish) a narrow secluded valley (in the mountains)
  subtype:  #gully  deep ditch cut by running water (especially after a prolonged downpour)
     subtype:  #arroyo  (southwestern United States) a stream or brook
     subtype:  #draw  a gully that is shallower than a ravine
     subtype:  #wadi  gully or streambed in North Africa and the Middle East that remains dry except during rainy season
  subtype:  #holler__hollow  a small valley between mountains; "he built himself a cabin in a hollow high up in the Appalachians"
     subtype:  #dell__dingle  a small wooded hollow
  subtype:  #nullah  a ravine or gully in southern Asia
  subtype:  #ravine  a deep narrow steep-sided valley (especially one formed by running water)
     subtype:  #canyon__canon  (North America) a ravine formed by a river in an area with little rainfall
     subtype:  #gorge  a deep ravine (usually with a river running through it)
        subtype:  #gulch__flume  a narrow gorge with a stream running through it
        instance:  #Grand_Canyon  #Olduvai_Gorge
  subtype:  #rift_valley  a valley with steep sides; formed by a rift in the earth's crust

No statement uses or specializes #valley; click here to add one.