ANNWN. The Celtic otherworld is known in Welsh as Annwn or Annwfn, variously analyzed as connoting "nonworld," "within-world," or "very deep." There is no formal description of this world in Welsh, and allusions in medieval Welsh texts and folklore suggest that it had many aspects. Its identification in medieval times with Hell and in modern folklore with fairyland is, of course, secondary. It is sometimes located below ground and is entered by subterranean tunnels, or it may be below the waters of a lake. Both concepts occur in medieval texts and in recent folktales. In the "Four Branches" of the Mabinogi (c. 1060–1120), the medieval Welsh collection of mythological tales, Annwn is conceived of as a world adjacent to the natural world, between which there are no boundaries but an awareness of a new dimension. Thus the hero Pwyll travels from his own land of Dyfed in southwestern Wales...