The Sass De Preja Buia, located in the North West area of Sesto Calende, is a natural site. The stone was declared a national monument and belongs from the Quaternary period, when it was transported near Lake Maggiore during glaciations. There have been a number of popular tales surrounding this ancient stone including one involving Jupiter punishing Venus and a fisherman being transformed into a fire-breathing dragon. The fisherman’s wife died while protecting her children and so was transformed into a hen-shaped stone protecting her chicks.