Careful on-site inspections, an analysis of the quality and quantity of the stylistic features, and a study of the problems afflicting the city, led to the conclusion that the lighting design for the old city centre, treated as one big monument, ought not to be altered too drastically. Rationalising, unifying and technologically updating the existing appliances and light sources would produce instantly appreciable results in terms of the urban master plan´s visual qualities, without really altering the existing layout. So the ever-present wrought iron lanterns were left alone, replacing their old light sources with the latest metal iodide bulbs with ceramic burners to boost luminescence and unify colour temperature (with high chromatic rating) to create a sense of continuity and order right across the urban fabric. Specially designed "Radius" (iGuzzini) twin appliances were used to replace the old and now obsolete devices. 120° blades of light, optical cut-out directed towards the road way, symmetrical optics and a special diffuser shield directed towards the top part of facing façade provide the streets and buildings with smooth and constant lighting, including good luminescence ratings for the horizontal and vertical planes and no unwanted glinting to ensure a more pleasant setting. The lighting appliances cause no visual impact either at daytime or night time.