The Ossola is a leaf-shaped complex of Alpine valleys in the northern tip of Piedmont bordering on Switzerland, wedged between the Swiss cantons of Ticino and Valais. Seven valleys make up the area (Vigezzo, Antigorio, Divedro, Formazza, Anzasca, Antrona, Bognanco) branching off the central river plain of the main Ossola Valley, which contains a number of ancient little towns and villages.
The geographical and administrative centre is Domodossola (pop. 20,000), the “capital” of the area, situated on the northern part of the plain. Twinned with the Swiss town of Brig on the other side of the Simplon Pass, it lies on the ancient route to the Pass and to the high Alpine passes of the Formazza Valley, and has all the characteristics of a frontier trading town.

Domodossola has since 2003 boasted a UNESCO World Heritage Site, the Sacro Monte Calvario, which is also a special nature reserve of Piedmont region, set on the Mattarella Hill above the town. The fifteen chapels in the Calvario complex fully reflect the local Ossola culture, and were built with the contribution of the best local artists of the 17th century, who introduced the Baroque style to the area.