The Khyber Pass is a 45-55km long pass through the Sefid Koh mountains, part of the Hindu Kush range. It is one of the most important passes between Afghanistan and Pakistan.
The pass heads northwest from near Peshawar to Kabul, and is within Pakistan's control along almost its entire length. A road was built through it in 1879 and a railroad in the 1920s.
Armies have taken advantage of the pass since at least 330 BC, when Alexander the Great and his army marched through to reach India.
