Originally ''told'' as a Mythological Tale (14th Century AD) of The Ancient Welsh Peoples – ''Caer Sidi'' was claimed as a ''Great Mystical Fortress'', which may have ''existed'' in The Welsh Underworld known as ''Annwn''. This massive Castle was said to have been mad (in large portions) of thick and transparent glass. It was ''garrisoned'' by many ''Warrior Spirits'' (perhaps the deceased soldiers of many lost and won battles). Some state that Caer Sidi was a much later concept used for King Arthur's famed (and equally mystical) ''Camelot''.
