Depiction in films
Twilight Sparkle and her friends are seen in this castle in My Little Pony Equestria Girls: Rainbow Rocks, gathering books for the castle's library, when suddenly Twilight notices a book vibrating. The book has Princess Celestia's cutie mark on the cover. She opens it and finds out that her friends from Canterlot High School are in trouble. Through research, she discovers that three sirens were banished to the human world by Star Swirl the Bearded. She makes some adjustments to the Crystal Mirror from the first film to make it able to open at any time, as opposed to every thirty moons.
The castle appears in the Rainbow Rocks film screenplay novelization My Little Pony: Equestria Girls: Rainbow Rocks: The Mane Event.