THE MONUMENTAL BUILDING
What today remains of the old Sforzesco Castle is only a part of the original building restored by the Sforza family after the Milanese citizens had destroyed the Visconti Castle in 1447. At present, the Castle is a quadrilateral enclosing the PIAZZA DELLE ARMI, with its central tower facing the city designed by Filarete and later restored by Luca Beltrami and two cylindrical towers covered with bosses on each side (the TORRIONE DEI CARMINI and TORRIONE DI SANTO SPIRITO). At the beginning of the 20th century, some new buildings, which now house offices, were added to the walls facing south and west. The TORRE DI BONA DI SAVOIA is built on one side of the Rocchetta, just near the place where there was the old PORTA GIOVIA, one of the medieval gates providing access to the city. The FOSSATO MORTO (dead moat), which can be seen today around the inner walls of the castle, was the original moat around the medieval town walls.
The other part of the quadrilateral is covered by the ROCCHETTA and the DUCAL COURTYARD. The Rocchetta is the most protected area. Situated in the northwestern part of the castle, it is provided with high windowless walls, an inner courtyard and a square tower facing the surrounding countryside named TORRE CASTELLANA. On the ground floor of this tower is the SALA DEL TESORO (Treasury room), which contains the beautiful frescos painted by Bramantino. The Ducal Courtyard encloses the TORRE FALCONIERA. On the ground floor of the tower is the Sala delle Asse decorated with paintings by Leonardo da Vinci. On the first floor is the Sala XX, which was the bedroom of duchess Isabella d'Aragona, Gian Galeazzo Sforza's wife.
The U-shaped Ducal Courtyard encloses a pretty garden. On the short side is the PORTICO DELL'ELEFANTE, named after a fresco that is painted on the arcade. An elegant ramp of stairs leads to the LOGGETTA DI GALEAZZO MARIA, the ducal loggia on the first floor. The moat enclosing the above-mentioned quadrilateral was in its turn surrounded by another circle of defensive walls built during the Renaissance period with the aim of protecting both the walls to the east and west and the façade on the back facing the Sforza family's garden, the so-called BARCO. This second circle of walls was called GHIRLANDA. Provided with three circular towers and connected to the inner space by means of the RIVELLINI, (RIVELLINO DI SANTO SPIRITO, RIVELLINO DEI CARMINI), the Ghirlanda was destined for defensive purposes in case of attacks coming from the countryside.