Portland has an extinct volcano sitting right in the middle of the city, so naturally at some point a group of grown men decided the appropriate use for it was racing homemade cars down the side.  The Portland Adult Soapbox Derby started in 1997 after Paul Zenk saw a gravity race in San Francisco, came home, sat down at the Horse Brass Pub with Eric Foren and realized Portland already had the hill - Mt. Tabor.  The first race was six guys and six homemade cars.  This last Saturday, there were 42 teams.  And calling them “cars” is being generous. Some look engineered within an inch of their lives. Others look like an art-school project escaped, found wheels and developed a death wish. They can hit around 50 mph, which feels like important information when the vehicle in front of you appears to include beer kegs and a dining table.
More pics and information here