Piazza del Duca is a central location for the Summer Jamboree festival, thanks to a vintage market and a food&drink area right in front of Rocca Roveresca,
Palazzo del Duca is situated exactly in front of Rocca Roveresca. Erected by Guidubaldo II della Rovere in the middle of the 16th century according to a project by Gerolamo Genga, it was enlarged in the following decades by his son and heir Francesco Maria II, the last representative of the dynasty, who altered the symmetry of the façade by placing the entrance portal on the left-hand side. The palace was not built as a permanent residence for the Duke, but as a place for the court and its illustrious guests who could admire the military parades that were taking place in the square from the windows.
The palace overlooks the square named after Giovanni Della Rovere. The square has some unique features for Renaissance: there are no religious buildings and the so-called Fontana delle Anatre (o dei Leoni) (Fountain of Ducks or of the Lions) is situated in an off-centred position, thus confirming the military use of the space.
The fountain was built between 1599 and 1602 upon order of Francesco Maria II della Rovere to celebrate the reclamation of the Saline marshland. The ducks represent the birds that used to live in the damp area, whereas the presence of water represents the ability of man to control water, a former carrier of disease and now a modern symbol of prosperity.
Palazzetto Baviera overlooks Piazza del Duca and was built, together with the Rocca, by Giovanni Giacomo Baviera, maternal uncle and lieutenant of Giovanni della Rovere, perhaps according to a project by Baccio Pontelli, as suggested by the harmonious proportion of the small courtyard.