The Zoobomb Pile – West Burnside at S.W. 13th Avenue, Portland, Oregon

This assemblage, known as the "Zoobomb pile," isn’t exactly a sculpture. Zoobomb is a weekly bicycling activity in Portland, Oregon, United States during which participants ride bicycles rapidly downhill in the city’s West Hills. Riders often dress up in costume or decorate their bicycles There is an emphasis on unusual bicycles, first and foremost the children’s bicycles or "minibikes," but extending to tall bikes, swing bike, choppers, non-functional bicycles, skateboards, longboards, etc. The Zoobombers are made up of a wide demographic, with a tendency towards young adults.

Though many riders bring their own bicycles, the participants maintain a "Zoobomb pile," This is a tower of minibikes anchored to a bicycle rack at the Zoobomb meeting point at the corner of West Burnside Street and S.W. 13th Avenue. These are spare bikes that are used as loaners for would-be Zoobombers who don’t have their own bikes. The pile has become a local landmark.