In the foundations of the castle there is a secret room filled with amphoras containing magic potions. The most immediate effect seen on living beings consuming some of these potions is an increase in size which makes them gigantic. These potions also seem to be the famous secret coveted by the Elves that prompted King Rulo to bring his people to Dreamland.
During the season 4 we discover that the castle was formerly much larger and that a large part of the old building collapsed in the sea with a piece of the cliff on which the castle is built. This part, unlike the one that have known, to keep statues, frescoes and tappsestries showing that the castle originally belonged to the elves. We also discover a cave with an entrance to the sea which is under the castle and which has been the theater of a fierce battle between an alliance of Elves and Sirens against humans, some of which were perhaps the ancestors of Bean because they used the same black lightning power as the latter possesses.