The group holding out there now - the National Resistance Front of Afghanistan (NRF) - recently reminded the world of the valley's strength. "The Red Army, with its might, was unable to defeat us... And the Taliban also 25 years ago... they tried to take over the valley and they failed, they faced a crushing defeat," Ali Nazary, the NRF's head of foreign relations, told the BBC.
The long, deep and dusty valley stretches about 75 miles (120km) - south-west to north-east - to the north of the Afghan capital Kabul. It is protected by high mountain peaks - rising 9,800ft (3,000m) above the valley floor. They are an imposing natural barrier - protection for the people living there. There is only one narrow road in, which winds its way between large rocky outcrops and the meandering Panjshir River.