By lighting public outdoor spaces it is important to know the programme of activities so that the proposed lighting fulfils the specific needs. The light employed has to articulate the urban space by accentuating some areas; by creating this focal points of attraction the environment becomes more ‘readable’. By creating a hierarchy of brightly lit and less illuminated parts of a city important views, panoramas and vistas, will be still perceived during the night. Formal and aesthetical qualities of the public space have to be taken into account too. Also the spatial characteristics of landmarks and sculptures have to be underlined by the lighting. By balancing all the lighting effects in the public realm in a subtle way the presence of sources of light will not be noticed.