The castle of Llyr. [electronic resource]
- 1st ed.
- New York : Holt, Rinehart and Winston, 1966.
- 201 p. : ill. ; 24 cm.
When Princess Eilonwy is sent to the Isle of Mona for training, she is bewitched by the evil enchantress Achren, so Taran and other friends must try to rescue her.