In this chill, blue-sky early morning, pilgrims walk steadily clockwise around the Potala Palace in Lhasa, Tibet.
Previously the home of 14 Dalai Lamas, it is perhaps the most dramatically recognisable face of Tibetan Buddhism.
Buddhism themes Tibet and at nearby Jokhang Temple, perhaps the most holy of places for Tibetan Buddhists, the same is happening.
For this kora - the morning procession - is an important part of pilgrimage to these places. The faithful walk around Potala Palace before making their way inside to the Jowo Shakyamuni Buddha statue, which is perhaps the single most revered object in Tibetan Buddhism.
And I find myself caught in the movement of it. Going along with it. These people, moving with single purpose, seem like a massive human dynamo generating power.
They carry both short and long strands of prayer beads, clicking them off with a thumb as they walk.
On these, they count the number of times the mantra Om Mani Padme Hum is recited. Mani means jewel, padma the lotus flower, the sacred Buddhist bloom. Six syllables repeated over and over, especially by devotees of the Dalai Lama.
Many have hand prayer wheels - canisters on handles that are also spun clockwise. And wrapped around the axle of these mani wheels is that same mantra Om Mani Padme Hum. Tibetan Buddhists believe that saying this Sanskrit mantra, silently or aloud, calls the powerful blessings of Chenrezig, the embodiment of compassion.
Then there are the bigger prayer wheels - rows of them, gold and perhaps almost as big as a 44-gallon drum, suspended vertically and also spun clockwise. Each turn spinning out the mantra . . . Om Mani Padme Hum.
The more times it is said and the more times the prayer wheel is spun and the more kora are walked, the more the mantra is multiplied. Spiritual blessings and wellbeing are spread far and wide.
I can almost see those six syllables flying off into the air, spun out with each cycle, by centrifugal force. Disseminated like seed against the blue sky up here at an altitude of 3600m.
Other pilgrims on the edges of this body of people move more slowly. These are pilgrim prostraters. While some walk here to repeatedly prostrate themselves at Potala or Jokhang's gates, these beside me now may have travelled days, weeks or even years on pilgrimages to Lhasa, covering the entire distance in prostrations.
They stand straight, raise their palms together, hands above their heads, touch crown, brow, throat and back to heart, and then bend forwards and touch the ground, kneeling and pushing forward to lie flat in a straight line, face down.
Then they quickly push back up off the floor, stand and repeat the prostration.
I am here on a bespoke cultural tour through China, Tibet and Nepal with the Leederville company Travel Directors, and pleased to have these intimate, thoughtful moments.
At Ganden Monastery, 40km outside Lhasa, I see a group of young people who have come a long distance like this, some with hide aprons, and with wooden pieces in each hand upon which to lean and slide.
Outside Tashilhunpo Monastery in Shigatse, about 300km from here and founded by the First Dalai Lama in 1447, I watched two prostraters moving slowly along a street's gutter, pads tied to their knees with rope.
Beside them was a stream of humanity, counting off beads, spinning prayer wheels, murmuring their mantra, the six syllables drifting up and away like chains of manuscript musical notes in the clear, thin air.