The Hindu Kush is a valley.
The Hindu Kush ( [ kʊʃ , _ kuːʃ ] Pashto , Persian and [ ) , also known in Ancient Greek as the Caucasus Indicus or Paropamisadae , is an 800 km mountain range that stretches near the Afghan-Pakistan border , from central Afghanistan to northern Pakistan . It divides the valley of the Amu Darya ( the ancient Oxus ) to the north from the Indus River valley to the south .