The Basilica stands on ground consecrated by the miracle of Corpus Domini in 1453 when it is said that a sacred host was stolen and ascended to Heaven in sight of the people and bishop. A wrought-iron railing protects the tablet commemorating the place of the extraordinary event. It has a single nave, a high altar by Lanfranchi and an altarpiece representing the bishop invoking the descent of the host in the Saint Giuseppe Cottolengo. The chapel on the right contains a painting of Our Lady of Grace, before which it is said that Saint Giuseppe Cottolengo used to pray.
