Khyber Pass

The most practicable of all the openings through the Khyber Mountains, is the only one by which cannon can be conveyed between the plain of Peshawur, on the right bank of the upper Indus, and the plain of Jelalabad, in Northern Afghanistan. It is 30 miles in length, being here and there merely a narrow ravine between almost perpendicular rocks of at least 600 feet in height. It may be said to have been the key of the adjacent regions in either direction from the days of Alexander the Great to the Afghan wars of 1839-42. Here a British army, on its retreat from Cabul in January, 1842, was absolutely annihilated.