The Ice Ruin, or Ice Castle as it is often referred to by players due to its appearance, is a type of ruin found only in the Frozen Land. Ice ruins are comprised of Ice Ruins Cubes.
Ice Ruins are the most difficult ruins to advance in due to the extreme power of its denizens. Its guardians include a wide cast of creatures including Icebears, Werewolves, Ice Elementals, and Behemoths. Its boss is the Ice Fairy.
The chest for the Ice Fairy can be retrieved without fighting the boss by breaking out one ruins block with a Steel Pickaxe