An open river valley (in a hilly area).

Roget 252: concavity, depression, dip; hollow, hollowness; indentation, intaglio, cavity, dent, dint, dimple, follicle, pit, sinus, alveolus^†, lacuna; excavation, strip mine; trough etc. (furrow) 259; honeycomb.    cup, basin, crater, punch bowl; cell etc. (receptacle) 191; socket.    valley, vale, dale, dell, dingle, combe^†, bottom, slade^†, strath^†, glade, grove, glen, cave, cavern, cove; grot^†, grotto; alcove, cul-de-sac; gully etc. 198; arch etc. (curve) 245; bay etc. (of the sea) 343.    excavator, sapper, miner.    honeycomb (sponge) 252.1. ... show more

Dutch: vallei, dal