The Sanctuary was built in the early seventeenth century to cope with the growing number of worshippers who began to flock to its small chapel following the Marian apparition. The first project was entrusted to Marco Nicolò Balestri and later completed by G.B. Aleotti. At the centre of the apse is the marble High Altar which houses the Madonna and Child by Garofalo. This fresco was located in the early church and was transferred here along with the wall; the images of SS. Nicolò and Giacomo, patrons of the two parishes of Argenta, were later added by Balestri