Yarlung Tsangpo Spins

Down the deepest gorge on Earth: out of a rock tunnel into the Yarlung Tsangpo canyon, under prayer flags strung from rim to rim, out over the rock and back down, and round the great bend, spiralling round a snow peak, to a Tibetan village by the river.

• Series: Canyons
• Length: 1.5 km
• 20 marbles a race, about a minute; every race is free