In graffiti slang, "heavens" are throw-ups (basic, quick representations of a writer's name) painted on an overhead highway sign (whether attached to a bridge, or free-standing). Heavens are dangerous to paint, not only because of the danger of falling 30-50 feet into traffic but due to the great risk of being seen and possibly caught. But for those very reasons, they carry high prestige, and if painted on the back of the sign, heavens can often run for years in areas where other graffiti is buffed within hours.