The original medieval core of Palazzo Ducale is its tower, also known as La Grimaldina or Torre del Popolo (People's Tower). Built around 1298, it became a symbol of the Republic of Genoa's political power. From the 13th century through the 1930s, the tower served as a jail for political prisoners, conspirators, anarchists, and common prisoners, including Giuseppe Garibaldi, credited with helping to unify Italy, and famed violinist Niccolò Paganini. Paintings, engravings, and etched graffiti left by the inmates can still be seen on its walls.