To get from Kabul to the agricultural project where I work in Pul-e-khumri you have to drive through the Salang Pass, it is the major mountain pass connecting northern Afghanistan and Kabul province.
The pass crosses the Hindu Kush but is now bypassed through the Salang tunnel (see photos), built by the Soviet Union in 1964, which runs underneath it at a height of about 3,400 m. The road through the pass has carried heavy military traffic in recent conflicts and is in very bad repair.
On February 9, 2010, the pass was hit by multiple avalanches. According to press reports the road through the pass was hit by 17 avalanches, killing dozens, burying miles of highway, and trapping the vehicles in the Salang tunnel.
The road is very bad but still very much worth the drive because the views are stunning, especially now with the mountains covered in snow.
Source used for this blog: http://en.wikipedia.org/wiki/Salang_Pass