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 dress code motto is "Bare as you dare". Full and partial nudity is encouraged, but not mandatory, on all rides. Any mandate to cover intimate parts is forbidden; this is a distinguishing feature of WNBR against other cycling events. Creative expression is also encouraged to generate a fun and immersive atmosphere during the ride, capture the attention and imagination of the public and media, and make the experience more personalized and fulfilling for the riders. Body art, such as body painting, are common forms of creative expression, as well as costumes, art bikes, portable sound reinforcement systems (such as public address systems, bullhorns and boomboxes) and musical instruments or other types of noisemaker. Cyclists ride during the World Naked Bike Ride in Mexico City. More photos from around the world, probably "NSFW," depending on where you "W."