Tir Na Nog (Irish for “Land of Youth”) is the location for this classic 1984 ZX Spectrum game, developed by Greg Follis and Roy Carter for Gargoyle Games.
You play Cuchulainn, a long-haired young man who has “departed the land of the living” (ie. died) and who finds himself walking in an afterlife patrolled by nasty creatures called Sidhe, which must be avoided at all costs.