The itinerary leaves from the SC road Castagnola-Sorzano and continues leaving on the right a concrete building used as drinkable water reservoir, to reach the oratory of San Grato.
If you go ahead, after a few hundred meters, you will reach an open area with a southern exposure called "Piana dei Ginepri", offering beautiful views over Sizzone valley, Borgomanerese and upper Novarese areas. In Sorzano, among centuries-old chestnut groves, you will find an 18th century settlement consisting of rural buildings with the characteristic rye roof, known as "taragn".
When you reach the lowest point of the itinerary, after crossing rio Fanteria, you will find the rests of an ancient tannery used until the 1920s. The trail climbs then uphill towards Bertagnina country hamlet, consisting of more settlements. A detour leads to chapel Prinetti, built in memory of the massacre committed here by the Nazi-Fascists in August 1944.
At Cascina Lanfranchini, after visiting San Carlo Church, go ahead westwards towards the trail called "degli Ozenghi": the trail develops at first across a chestnut grove giving way to a chestnut coppice woodland and ending in a high-trunk beech woodland, until you reach Rasco country hamlet where you can see San Antonio church and some characteristic houses with galleries, typical of lower Valsesia.
The itinerary continues towards Castagnola, whose main square houses the church dedicated to San Lorenzo and enlarged according to the project by architect Alessandro Antonelli (1798-1888). A conifer-lined path indicates the presence of a "Parco delle Rimembranze", where the fallen of World War I are commemorated. A steep trail leads to Mt. Calvario, a wonderful panoramic point over the whole alpine chain and the Po Plain.