The chief peaks in the province are Kaisargarh (11,300 ft.) and Pir Ghol (11,580 ft.) in Waziristan; Shekh Budin (4516 ft.), in the small range; Sikaram (15,621 ft.) in the Safed Koh; Istragh (18,900 ft.), Kachin (22,641 ft.) and Tirach Mir (25,426 ft.), in the Hindu Kush on the northern border of the Chitral agency; while the Kagan peaks in Hazara district run from 10,000 ft.
Geographically the Safed Koh is not an isolated range, for there is no break in the continuity of water divide which connects it with the great Shandur offshoot of the Hindu Kush except the narrow trough of the Kabul river, which cuts a deep waterway across where it makes its way from Dakka into the Peshawar plains.
The extent of Asoka's dominion included all India from the thirteenth degree of latitude up to the Himalayas, Nepal, Kashmir, the Swat valley, Afghanistan as far as the Hindu Kush, Sind and Baluchistan.
The last of those to leave before the gate was shut were Albanians under Salih Kush.
Diodotus and his successors were able to maintain themselves against the attacks of the Seleucids; and when Antiochus III., "the Great," had been defeated by the Romans (190 B.C.), the Bactrian king Euthydemus and his son Demetrius crossed the Hindu Kush and began the conquest of eastern Iran and the Indus valley.