Annwn or Annwyn (pronounted "a-non") is the land of the dead, the underworld or Afterlife, in Welsh mythology. It is said to lay far in the west and could be accessed by the living through a door located at the mouth of the Severn once a year. Surviving from pre-Christian Celtic mythology, it's neither Heaven nor Hell in the Christian sense, and the living can enter spiritually or corporeally.