The Visconti Castle, whose ancient origin dates back to the 9th century, is cited in a will spread out in Gallarate on 22 June 1251 by the notary public Marcellino de Angleria. Testimony of the Visconti presence, the family was present in Somma since 1250, it is the castle that was born as a fortress of defense on the border of the Duchy of Milan. The Visconti fortress experienced its greatest splendor from the year 1448, when the brothers Francesco and Guido Visconti, to escape the contrasts with the Ambrosian Republic, which replaced the lordship Viscontea in Milan, they took refuge in their ancient property of Somma. Within a few years the noble dwelling was largely rebuilt. In this way space was gained and the new residence of the Visconti could be strengthened. Not to be missed, guided tours on weekends and holidays.