On the fifth day of teaching there was a rainbow. Not the usual arc - which would still have been glorious against the dry earth and high mountains - but a perfect, multicoloured circle around the midday sun.
I had never heard of such a phenomenon before, but some of the Buddhist festival regulars just nodded with satisfaction. 'Ah, another one. They often happen at these events.' We were gathered in the small village of Tabo, in the valley of Spiti behind the military inner line on the India side of the India-Tibet border.
Usual population 610. Current population 20 times that and growing by the hour. Not just Buddhists, of which there were thousands, local, Tibetan and Western, but also hundreds of Christians, Jews, Hindus, Muslims, as well as those - myself among them - who do not belong to any church.
It was open to all, and for those who could not understand Tibetan or Hindi there was simultaneous English translation on FM radio.
We were all there for the Kalachakra, an advanced Buddhist initiation ceremony, that takes place only rarely and only at the full moon.
But for the majority of people there, this was primarily a chance to listen for two weeks to the Dalai Lama, god king of the Tibetan people and - because of his persistent and peaceful resistance to the invasion of his country by China, and his Nobel Prize for Peace - something of an icon in the West as well.
I talked to Geshe Sonam Wangdui, who has been abbot of Tabo since 1978. He explained that the plan to host a Kalachakra to celebrate the 1,000-year anniversary of the ancient temple of Tabo, with its beautiful wall paintings, was first proposed in 1991.
