UNESCO describes the Site Piedmont and Lombardy Sacred Mounts as follows: The nine northern Italy's Sacred Mounts are composed of groups of chapels and other architectural elements built within the end of XV and the end of XVII century and dedicated to different aspects of Christian Faith. In addition to their symbolic religious meanings, these places are characterized by a remarkable beauty thanks to the careful integration of architectural elements into the surrounding natural landscapes: hills, woods and lakes. Furthermore they boast very important works of art like frescos and statues.

UNESCO World Heritage Committee has put the Site on its List for the following reasons:

The realization of an architectural and sacred art's work into a natural landscape for didactic and religious aims, finds its highest expression in northern Italy Sacred Mounts and it has deeply influenced following developments of this phenomenon in the rest of Europe.

Sacred Mounts of northern Italy represent the successful integration into a landscape of remarkable beauty of architecture and fine arts realized for religious aims during a critical period of Catholic Church history.

UNESCO Site's Sacred Mounts are mainly located in the Alpine arc, close to lakes or at the bottom of valleys crossed by river Po's tributaries and by important old routes. The complexes' panoramic and prominent locations on hills or mountains and their subdivisions into chapels, let them become territorial reference points easy to identify; we don't have to forget that creating sort of territorial reference points was probably one of the aims for such locations, considering that sacred mountains strategical position marks the northern limit of the Po valley, which was, at that time, symbolically protected by them, that is by the Christianity itself.
There is an important thread ideally binding these nine Sacred Mounts: the first crib of Greccio, made by Saint Francis of Assisi, the Holy Representations, the protection of the Holy Land, the Sacred Mounts foundations (first by gerosolimitani then by counter-reformists) and the Viae Crucis, almost all the above stories in fact tell us about Franciscan fathers who had been fundamental for all complexes' building. Some had been the inventors, like Bernardino Caimi in Varallo, Tommaso of Firenze in Montaione and Michelangelo of Montiglio in Belmonte; some the designers, like Cleto of Castelletto Ticino in Orta, or the preachers like Giovan Battista Aguggiari in Varese, Fedele of San Germano in Oropa, Gioacchino of Cassano and Andrea of Rho in Domodossola. More we remeber that between 1731 and 1751 it was again the Franciscan Leonardo of Porto Maurizio who built five hundred and seventy-two Viae Crucis throughout Italy; we owe nineteenth-century-restoration and renewal of Crea's Sacred Mount to Franciscan fathers Costantino Cerri and Giuseppe Latini. Observants or Capuchins, that are disciples of the poor of Assisi, are the most sensitive and active champions of the theatre-, sculpture- and painting-representations.

Dedications and histories told in each complexe remind both of pre-existent local devotions and of religious and cultural foundation times. Therefore in Varallo prevails the representation of Jesus Christs' life, in Orta of Saint Francis of Assisi, in Oropa of the Virgin Mary, while in Varese and in Ossuccio they represent the Marian Rosary prayer with its fifteen Misteries. Wishing to follow again the steps of Christ's Passion, like the Jesus's Via Dolorosa in Jerusalem (that is 'Very Painful Viae'), they modified the Sacred Mount of Crea and built the Sacred Mounts Calvaries of Domodossola and Belmonte. In Ghiffa instead Holy Trinity's devotion resulted so difficult and abstract to represent that, in the end, they went back in part to a much usual and immediate issue: the Via Crucis.