Symbol of Milan, the Duomo is one of the most known and valued monument abroad. The majesty of the cathedral together with the impressive number of figurative carvings groups make this site one of Milan’s most picturesque and recognizable settings. The lighting project gained significant importance since this square was the scene in 1877, of the first Italian public electric lighting experiment made with arc lamps… Goal of the project was to grant the reading of the whole construction, lighting the marble surface in a uniform way, still maintaining a good balance between light and shadows on the upper statuary. Accurate lighting techniques have been used. The projectors have been installed on the adjacent buildings and few on the closest poles. The remarkable distances involved (up to 130 meters) imposed a strict control of the luminous flux and anti-glare filters.