The Castle Hill of Grosio is dominated by two castles. The Old Castle (Castello Vecchio) was probably built at the end of the 10th century. The Castello Nuovo was built as a stronghold between 1350 and 1375 due to the military-strategic needs of the 14th century.
The castle is surrounded by a double defense wall and had next to e solid keep even a fortified internal tower. Apart from a military expedition by Giovanni Cane in 1376 to Bormio, which had its starting point here, the Castello Nuovo was never involved in military confrontation or siege. Today the castle is only preserved as a castle ruin because after 1526 the new political power in Valtellina ordered the destruction of all fortifications in the valley. That way the dominion of the Three Leagues wanted to avoid any potential danger that could emanate from their own castles.
During the period of the Bündner Wirren (1620-1639), the Thirty Years' War in Europe, the structure was used by the French under Duke Rohan as a military base and got partially restored. The Castello Nuovo is nowadays the best-preserved example of all the historic defensive structures in the Valtellina.
Between 1992 and 1997 in the area of the Castello Nuovo archaeological excavations could document the remains of a bronze and iron age settlement, dating from the middle of the 2nd to the end of the 1st millennium BC. Some of the small finds are now exposed in the excavation museum.
References:The Château de Foix dominates the town of Foix. An important tourist site, it is known as a centre of the Cathars. Built on an older 7th-century fortification, the castle is known from 987. In 1002, it was mentioned in the will of Roger I, Count of Carcassonne, who bequeathed the fortress to his youngest child, Bernard. In effect, the family ruling over the region were installed here which allowed them to control access to the upper Ariège valley and to keep surveillance from this strategic point over the lower land, protected behind impregnable walls.
In 1034, the castle became capital of the County of Foix and played a decisive role in medieval military history. During the two following centuries, the castle was home to Counts with shining personalities who became the soul of the Occitan resistance during the crusade against the Albigensians.