The Otherworld has been described in Irish poetry and tales as being a land of paradise, happiness, and summer. It is often described as a series of islands where the various deities and ancestors live. Many mythological heroes, such as Cúchulainn journeyed to Otherworld realms.
(the giant Cuchulain)To some it is a version of heave but to most Christian writers it was a version of hell. The Otherworld was hidden with magic and could be located in a variety of places from forests and rivers to castles and cottages that appeared at night and vanished in the mornings. Time is different in the Otherworld. For example, if a year passed in the Otherworld, centuries could have passed in the real world. Additionally, people there never aged. The Otherworld also seemed to be able to move from one location to another. It is believed that the idea of the Otherworld is mostly pre-Christian.
There is also a story of Arthur making a journey to the Otherworld gained possession of a magic cauldron--a pagan Celtic type of the Holy Grail--which furnishes inexhaustible food though 'it will not boil the food of a coward'.
Our book states, "the prototype of the grail was a Celtic vessel dispensing food and drink in an Otherworld atmosphere of perpetual youth and feasting."