The Kabul (ancient Kophes), which is the most important (although not the largest) river in Afghanistan, rises at the foot of the Unai pass leading over the Sanglakh range, an offshoot of the Hindu Kush towards Bamian and Afghan Turkestan.
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.
From Bamian it passes over the central mountain chain to Kabul either by the well-known passes of Irak (marking the water-divide of the Koh-i-Baba) and of Unai (marking the summit of the Sanglakh, a branch of the Hindu Kush), or else, turning eastwards, it crosses into the Ghorband valley by the Shibar, a pass which is considerably lower than the Irak and is very seldom snowbound.
From the foot of the Unai pass it follows the Kabul river, and from the foot of the Shibar it follows the circuitous route which is offered by the drainage of the Ghorband valley to Charikar, and thence southwards to Kabul.
It rises in the recesses of the Koh-i-Baba to the west of Kabul, its infant stream parting the Unai pass from the Irak, the two chief passes on the well-known road from Kabul to Bamian.