According to local tradition, it represents the last remnant of the ancient imperial castle built by Frederick Barbarossa in the highest part of the town, where his governor, Guelph VI, resided. It was destroyed in 1166 following the rebellion of the inhabitants against Barbarossa's oppression. ​It is a watchtower and fortification, part of Lombardy's architectural heritage, listed among the region's historic buildings. Its strategic location makes it a point of interest in the context of the Naviglio Canal and the ecomuseum itineraries of Gorgonzola.