Also spelled Hy-Brasil, Hy-Brassil, Hy Brassil, Hy Brazil, and assorted other ways.
Traditionally, the link between Ireland and Atlantis was through the mysterious sunken island of Hy-Brasil, located somewhere in the Atlantic. This island, which is said to have been named after the king of Ireland, Bressal, is said in local folklore to be visible once every seven years off the west coast of Ireland. Some believe this is a possible candidate for Atlantis, hence the naming of the ocean, the Atlantic Ocean.
Way back in 1684, the Irish historian O'Flaherty spoke about the enchanted island of Hy-Brasil:
"From the Isles of Arran and the west continent often appears visible that enchanted island called O'Brasail and, in Irish, Beg Ara.
Whether it be real and firm land kept hidden by the special ordnance of God, or the terrestrial paradise, or else some illusion of airy clouds appearing on the surface of the sea, or the craft of evil spirits, is more than our judgments can pound out."