Ice Castle features in Rudolph the Red-Nosed Reindeer: The Movie. It is the palace of Stormella.
It first appears briefly when Stormella and Ridley travel back there after Stormella closes off her bridge to the public.
It next appears when Stormella and Ridley via Stormella's crystal ball see Zoey crossimg the bridge.
It then appears when Rudolph and Leonard go there to rescue Zoey while Slyly stays behind in fear of Stormella's Wolves (though he does eventually go after them and free them and Zoey after stealing the key to the dungeon).
It last appears on Christmas Day when Ridley shows Stormella that Santa left her an ice statue of herself as a gift to make up for the statues accidentally destroyed by his elves Boone and Doggle.