Sacro Monte Calvario di Domodossola Special Nature Reserve was established in 1991 with the aim to safeguard the great artistic, historical, architectonic, and naturalistic heritage of the Sacro Monte. The Complex is made of the medieval Mattarella Castle, Rosminiani Fathers Monastery, Madonna delle Grazie Oratory, SS. Crocefisso Sanctuary, and the fifteen chapels of Via Crucis.