The World Naked Bike Ride (WNBR) is an international clothing-optional bike ride in which participants plan, meet and ride together en masse on human-powered transport (the vast majority on bicycles, but some on skateboards and inline skates), to "deliver a vision of a cleaner, safer, body-positive world." The first ride happened in Zaragoza (Spain) in 2001. The dress code motto is "bare as you dare".