In February each year they stage a mountain bike race through the town of Valparaíso (Chile). The bikers have race down narrow steps, over jumps and take tight corners by riding up walls on the outside of the curves.

Crowd control is almost non-existant, and riders have to keep an eye open for people getting in the way and stray dogs:

In case you thought that didn’t look too bad, take a look at some of the “fails”: