Some areas have a lingering connection to the primal forces of the world's birth. the Shadow Society and the Dark Circle both use these places for powerful magic. This is one of the two types of places where Changelings might be born (RPG concept)
The Kingdom of Tonophria in the north is beneath the ice. Accessible by tunnels and hidden passages going down, there is nothing but an expanse of ice reminicent of Antartica above. Possibly one of the most interesting Kingdoms in the saga.