From Passo Nota you climb the Mount Nota on the military path towards West and you reach Prà de la Ròsa, where, in a majestic and impressive succession of gorges, the path goes downhill to Malga Corno (Còr) (junction with 457 bis). It continues through the wild and beautiful Val Marcia and Val Gatum as far as Malga Tremalzo di Molina and then goes uphill for a short stretch. Across the northern slope of Mount Tremalzo it leads to Malga Pertèga with wonderful views of the Valle di Pur. A short distance later it joins up with path 456 coming from Malga Giù and heading for Bocca Casèt.
