Located in the Biellese Alps, the Sacro Monte di Graglia hosts the Santuario di Nostra Signora di Loreto, one of the area's four major sanctuaries.
Inspired by the Sacro Monte di Varallo, parish priest Don Andrea Velotti launched the project in 1605 after a pilgrimage to the Holy Land. His vision was 100 chapels depicting biblical scenes, but only 10 were built before his death in 1624.
In 1654, a new plan led by engineer Pietro Arduzzi and backed by Duke Charles Emmanuel II aimed to build a grand sanctuary centered on a replica of the Holy House of Loreto. Construction faced delays but continued; by 1684, four chapels on Jesus' early life were completed.
Between 1760–1769, architect Bernardo Vittone finished the sanctuary, preserving its Greek cross plan. The rough brick façade contrasts with the richly decorated Baroque interior. A Black Madonna statue was placed inside, linking it to the Santuario di Oropa.
The dome, 38 meters high, was painted with trompe-l'œil frescoes in 1780. The Holy House replica was moved within the church in 1788 and again in 1828.
Today, the sanctuary remains a pilgrimage site. The original chapels are in disrepair, but four chapels on Jesus' childhood are preserved. Nearby, a unique echo point can clearly repeat up to eleven syllables.