" A fascinating matter about Skellig Michael is that it is the westernmost sacred site along a long line of ancient pilgrimage places running from western Ireland through France, Italy and Greece, and then onto Mt. Carmel in the Palestine. This line, sometimes called the Apollo/St. Michael axis was known thousands of years before the advent of Christianity and linked the venerated holy places of St. Michael’s Mount, Mont St Michel, Bourges, Perugia, Monte Gargano, Delphi, Athens and Delos."
See sacredsites.com

Sanctuary of San Michele