B1
an area of low land between hills or mountains, often with a river running through it
Dictionary examples:
The valley was so deep, I yelled 'Hello!' and heard my echo three days later. (0.0)
Our valley's WiFi is so bad, we send emails by pigeon. (0.0)
Our valley's echo is so strong, it answers before you even ask. (0.0)
the Nile Valley (3.8)
the Ohio River valley (21.3)
There was snow on the hilltops but not in the valley. (53.9)