The citadel of Turin, built in the sixteenth century by the duke Emanuele Filiberto, became an expensive and obsolete object that hampered the enlargements during the nineteenth century. The Enlargement Plan for the capital designed by Carlo Promis (1851-1852) progressively reduced the military constraints facing the citadel. In 1856 the City Council decreed the demolition of the defensive structure. During the demolition one section of the building was spared: the donjon.
The central theme is the Project Financing, a complex financial instrument that can potentially be used to give a new life to a state property with a strong historical and architectural value and in a state of neglect, through the use of public-private partnerships.