The Madonna was honored on this site as early as the fourth century, but the oldest part remaining is the Romanesque campanile, built sometime around AD 1000.
When Guarini rebuilt the church in 1678 as a sanctuary dedicated to Mary, he retained the early tower.
His Baroque pilgrimage church is a feast for the eyes inside, lavishly decorated in colored marble inlay; pilgrims have added ex votos ever since its completion. In 1729, Filippo Juvarra added the oval chapel.
