The north-eastern portion of this range is of great altitude, and separates the headwaters of the Oxus, which run off to the Aral Sea, from those of the Indus and its Kabul tributary, which, uniting below Peshawar, are thence discharged southward into the Arabian Sea.
From the Khawak to the head of the Ghorband (a river of the Hindu Kush which, rising to the north-west of Kabul, flows north-east to meet the Panjshir near Charikar, whence they run united into the plains of Kohistan) the Hindu Kush is intersected by passes at intervals, all of which were surveyed, and several utilized, during the return of the Russo-Afghan boundary commission from the Oxus to Kabul in 1886.
Those utilized were the Kaoshan (the "Hindu Kush" pass par excellence), 14,340 ft.; the Chahardar (13,900 ft.), which is a link in one of the amir of Afghanistan's high roads to Turkestan; and the Shibar (9800 ft.), which is merely a diversion into the upper Ghorband of that group of passes between Bamian and the Kabul plains which are represented by the Irak, Hajigak, Unai, &c. About this point it is geographically correct to place the southern extremity of the Hindu Kush, for here commences the Koh-i-Baba system into which the Hindu Kush is merged.
The YashkunChitral-Kunar river (it is called by all three names) is the longest affluent of the Kabul, and it is in many respects a more important river than the Kabul.
It joins the Kabul river a few miles below the city of Kabul.
