Yartsa gunbu sells for big money in the top department stores of Lhasa
And there is a growing market outside of Tibet.
Although Tibet is modernising fast, it retains a deeply spiritual culture.
Even today,Tibetan valleys resound to distinctive and extraordinary calls to prayer.
The Tibetan horn may be the world's most unwieldy instrument
But its sound is unique.
Every morning,the nuns assemble for practice.
The air is chilly, but they soon warm up.
Monks and nuns comprise a substantial portion of society.
Largely self-contained and isolated.
Deep within the monastery
is the spiritual engine that drives much of Tibetan culture.
Buddhists believe in an endless cycle of rebirth in which the actions of this life
will impact on the next.
The goal of Buddhism is to escape from this earthly cycle of pain and suffering
by achieving a state of freedom called enlightenment.
The enlightened guides,or spiritual teachers,are called lamas.