Onbashira goes like this: every six years, thousands of local men (and very occasionally, a badass woman) replace the four pillars at each of the corners of Shinto shrine Suwa Taisha in Nagano, Japan. Four pillars at each corner makes for a total of 16 pillars. These pillars are fir trees cut from the nearby forests of the Suwa region where the festival takes place.

Once the trees are cut and felled (a tradition known as Yamadashi), they are left to sit for a month. Then, the festival's Satobiki half begins. The aforementioned locals strap these 10-12 ton logs to their bodies and slog them over the rivers and through the woods to Suwa Taisha. 

The odyssey's unforgiving topography means death is a reasonable hazard. Kiotoshi is the downward part of the festival featured in this thrilling video above, where the undaunted men (...and occasional badass woman) straddle the logs and let gravity take control as they careen down grassy hillsides. The logs hit the skids quickly, and viewers lining the course watch participants fall off and tumble wildly down the hill, all while trying to avoid being crushed in the tangle.

To end it, the logs are wrapped with rope and pulled upright at the shrine. Numerous men cling to the ascending pillars and put on a show once they're firmly in place. The festival just wrapped in May, so mark your calendars for six years from now to catch the next session of madness.