The Lost Citadel is a sacred magical place that is located in its own small demiplane and was the first true bastion of magical knowledge in all of Krynn. Originally constructed by the founders of the Orders of High Sorcery in 2645 PC, the tower housed all sorts of arcane secrets; however the founders were unable to control their magic without any sort of restrictions, which resulted in considerable devastation during the Second Dragon War. Instead the gods of magic decided to transport their tower beyond the Material Plane, to protect the lore stored within, as well as the mages themselves.
The three mages were then taught controlled magic by Lunitari, Solinari and Nuitari for over one hundred years, before returning the mages back to the Material Plane. The gods then closed the path to the Lost Citadel, forbidding entry to any mortal. It is believed however that a particular portal grants access to the tower every Night of the Eye, when coupled with a particular spell.
The Lost Citadel was described as being surrounded by knee-high fog, with delicate golden gates as its entrance, and a trio of diamond spires that rose high above the fog. The spires were set on a sparkling gold pentagon, and the tower bore no windows or balconies. The Lost Citadel pulsed with life and magic, and could be likened to a monstrous jewelled pendant.