Since 1400 ", writes a parish priest of 1700," a chapel or oratory has been erected beyond the mountains under the title of San Colombano, of reason and dominion of the community of Illasi, with a miraculous image of Maria Santissima (.. .). There is a rumor that it had a cemetery around it on the occasion of contagions suffered, to bury corpses, where there was a long and hooked fero to attract them to the burial ".
The church of San Colombano has always been at the center of the attention of popular piety, which on many occasions has resorted to the miraculous image mentioned above: a fresco (probably made on the occasion of the extension works of the church organized by the Pompeii family in 1600 ) placed, since 1823, above the main altar. Epidemics and famines experienced by the people of Illasi have had, over the centuries, the Madonna di San Colombano as a point of reference and reason for hope.
Of the many votive processions, today still survives after 150 years, that of the second Sunday of May, which commemorates the grace granted by the Virgin on the occasion of the "cholera morbus" of 1835.
Other frescoes, dating back to 1400, can be seen on the internal and external walls of the church. The two figures of saints on either side of the presbytery were recently discovered and restored, by the will of Don Alessandro Bennati.
The Municipality of Illasi proved to be the owner of the small temple around the middle of 1500; previously it seems to have belonged to the Pompei family. Over the centuries, numerous religious succeeded one another in the custody of the church.
The church was restored in 1970, with the contribution of the parishioners of Illasi.