The large wooden sculpture that stands in Piazza Guido Masi, behind the Castle of Conti Guidi, was donated to the city in 1987 by the artist himself, Mario Ceroli. It draws inspiration from the well known drawing of the Gallerie dell'Accademia in Venice in which Leonardo depicts the idea of proportion expressed by Vitruvius Pollione. The three-dimensional version of the work honors the modernity and dynamism of Leonardo's drawing in which Mario Ceroli had already been interested since the 1960s.