 According to tradition, the Roman road leading from Ponte Tresa to Monte Ceneri Pass ran through Arosio.By the Middle Ages it was a central town in the upper Magliasina valley, which was at that time was known as the Valle d'Arosio.The villages of Arosio, Breno, Cademario, Mugena Tortoglio and Vezio formed an economic and political unit.