About 20 kms south-east of Rangdum stands the Panzila axis, across which lies Zanskar, the most isolated of all the trans-Himalayan valleys. The Penzila pass (4,401m) is a picturesque tableland surrounded by snow-covered peaks. 

As the Zanskar road winds down the steep slopes of Penzi-la to the head of the Stod valley, the majestic " Drang-Drung" glacier looms into full view. A long and winding river of ice and snow, "Drang-Drung" is perhaps the largest glacier in Ladakh, outside the Siachen formation. It is from the cliff-like snout of this extensive glacier that the Stod or Doda tributary of the Zanskar River rises.

Zanskar is a tri-armed valley system situated between the Great Himalayan Range and the Zanskar mountains, the three arms radiating star-like towards the west, north and south from a wide central expanse. Here the Zanskar River comes into being by the confluence of its two Himalayan tributaries, the Stod/Doda and the Lingti-Tsarap rivers. It is mainly along the course of this valley system that the region’s approximately 14,000 strong, mainly Buddhist population, live.