Men ride a giant log down a mountainside. Held once every six years at the Suwa Grand Shrine, the Onbashira Festival involves felling fir trees more than a century old and weighing over ten tons, then dragging them down from the mountains by human strength alone to stand at the four corners of the shrine. The rite is said to date back more than twelve hundred years to the Heian period, and why it began remains imperfectly understood. Its most dangerous moment is Kiotoshi, when parishioners straddle the massive logs and plunge down a slope as steep as thirty-five degrees. People have been thrown off and killed. By raising new pillars, the community renews the power of its gods, descending the mountain alongside the trees to make the shrine new again.