Soon after the Paderno bridge, in the deep, green ravine dug by centuries of flowing water, the riverbed changes suddenly.

A series of rocks, spurs and crags break its gentle, quiet course into foamy rapids. The characteristic Tre Corni of Paderno rise out of the river bed at this point. Breaking against the rocks in in a variety of stone named “ceppo dell’Adda”, the water creates turbulent waves.

Hence, considering the features of this river segment, the idea of building a canal for boats sailing from Lecco was conceived already in the 1500s. This is the site depicted in Leonardo Da Vinci’s drawings, a recurrent stop on his journeys along the river Adda.

In the background of the painting "Virgin of the Rocks" (1483-1486) we notice the segment of the river Adda with the "Tre Corni alla Rocchetta".