The Reliquary is a unique Otherworld in that it channels the ideal of a treasure, a powerful, ancient, important treasure that might solve all of its seeker's problems.
It was only opened twice in recorded memory. Once by Percival, a member of the Circle of Merlin, who found the fabled "Holy Grail", and once by Aladdin, Godborn of Bastet, who retrieved a lamp holding Sibal Wilm Rion, a powerful Djinn. In 1994, a group of Godborns were tasked to open it once again to find a weapon capable of stopping an impending attack by the Titans Kronus, Gaia and Apophis.