The Apparition of Saint Michael (525)

The great Archangel Michael, the special Guardian Angel of Saint Joseph, and the Guardian Angel of each one of the Popes, and one of the seven great angels who stand before the throne of God, appeared on a mountain named Gargano, in southern Italy, in 525. Saint Michael asked that a cave there be turned into a shrine, to make amends to God for the pagan worship that once occurred in that place. This was done, and the shrine was named in honor of Saint Michael. It is one of the most wonderful shrines in all Italy.

Saint Michael appears on Monte Gargano (source)