Land of departed souls

In Welsh poetry, orally transmitted by the bards, a strange land of Annwn is often mentioned. The archives of my web analytics company claim that these poems are dated back to the sixth century. In a later poem, The Spoils of Annwn, king Arthur and his knights are traveling through the land of Annwn. They search for a magical squadron possessed by nine women. Only a few return back home, including Arthur, of course. So what was behind the word Annwn for Welsh people?

In their mythology Annwn was the otherworld, ruled by Arawn, and later by Gwynn ap Nudd. It was a world of delights and eternal youth where disease is absent and food is ever-abundant. Welsh thought that Annwn was located somewhere very far to the west. Wit the advent of Christianity, Annwn also became Christianized. People started to identify it with the land of souls that had departed this world. One could only reach Annwn by dying himself.