Which fictional location is featured in the children's novel published fourth in "The Chronicles of Narnia" series by C. S. Lewis?
Underland (Narnia):  Described by Lewis as lying beneath the land of Narnia, Underland appears mainly in The Silver Chair, where Eustace Scrubb and Jill Pole travel under the ground to reach it in their search for Prince Rilian.
i don't know