Even yet at rare intervals, like a phantom, Hy Brasil appears far out on the Atlantic. No later than the summer of 1908 it is said to have been seen from West Ireland, just as that strange invisible island near Innishmurray, inhabited by the invisible 'gentry', is seen--once in seven years. And too many men of intelligence testify to having seen Hy Brasil at the same moment, when they have been together, or separated, as during the summer of 1908, for it to be explained away as an ordinary illusion of the senses. Nor can it be due to a mirage such as we know, because neither its shape nor position seems to conform to any known island or land mass. The Celtic Otherworld is like that hidden realm of subjectivity lying just beyond the horizon of mortal existence, which we cannot behold when we would, save with the mystic vision of the Irish seer. Thus in the legend of Bran's friends, who sat over dinner at Harlech with the Head of Bran for seven years, three curious birds acted as musicians, the Three Birds of Rhiannon, which were said to sing the dead back to life and the living into death;--but the birds were not in Harlech, they were out over the sea in the atmosphere of Rhiannon's realm in the bosom of Cardigan Bay.[323] And though we might say of that Otherworld, as we learn from these Three Birds of Rhiannon, and as Socrates would say, that its inhabitants are come from the living and the living in our world from the dead there, yet, as has already been set forth in chapter iv, we ought not to think of the _Sidhe_-folk, nor of such great heroes and gods as Arthur and Cuchulainn and Finn, who are also of its invisible company, as in any sense half-conscious shades; for they are always represented as being in the full enjoyment of an existence and consciousness greater than our own. In Irish manuscripts, the Otherworld beyond the Ocean bears many names. It is _Tír-na-nog_, 'The Land of Youth'; _Tír-Innambéo_, 'The Land of the Living'; _Tír Tairngire_, 'The Land of Promise'; _Tír N-aill_, 'The Other Land (or World)'; _Mag Már_, 'The Great Plain'; and also _Mag Mell_, 'The Plain Agreeable (or Happy).'