According to legend, the line represents the blow with which St. Michael sent the devil to hell.
A mysterious imaginary line links seven monasteries, from Ireland to Israel. Is it just a coincidence? These seven sanctuaries are very far from each other, and yet they are perfectly aligned (siviaggia.it).
The Sacred Line of Saint Michael the Archangel represents, according to legend, the blow the Saint inflicted the Devil, sending him to hell.
In any case, it is surprising how well these sanctuaries are, in fact, aligned. But the details of such alignment are also astonishing: the three most important sites, Mont Saint Michel in France; the Sacra of San Miguel in Val de Susa; and the Sanctuary of Monte Sant’Angelo in the Gargano are all the same distance one from the other.