question: Who illustrated the novel in which the fictional location "The Underland" mainly appears?
answer: Pauline Baynes
context: Title: Rock of Eternity
  Passage: The Rock of Eternity is a fictional location appearing in comic book stories about or relating to Captain Marvel/Shazam!  published by Fawcett Comics and later by DC Comics.  It first appears in "The Marvel Family" #7 (December 1947) in the story "The Marvel Family Reaches Eternity".
  Title: Land of Toys
  Passage: The Land of Toys (Italian: "Paese dei balocchi" ) is a fictional location in the Italian novel "The Adventures of Pinocchio" (1883).  It is also known as "Funland" or "Playtime Land."  It is disguised as a haven of freedom and anarchy for boys and occasionally girls.  In the Disney film adaptation of the novel, the land is renamed as Pleasure Island.  The size and nature of such location is unclear (the Disney adaptation depicts it as a large, island-sized amusement park that parallels Disneyland itself, whereas the novel implies it is at least as large as a township); the ambiguity in the original name ("paese" can mean "country" or "land", but also "town" or "village") adds to the confusion.  To its unsuspecting visitors, it appears to be a fantastic place where boys and girls can do whatever they want with no consequences or law.  However, its real use is to de-evolve children for slave trade.
  Title: The Silver Chair
  Passage: The Silver Chair is a high fantasy novel for children by C. S. Lewis, published by Geoffrey Bles in 1953.  It was the fourth published of seven novels in "The Chronicles of Narnia" (1950–1956); it is volume six in recent editions, which are sequenced according to Narnian history.  Like the others, it was illustrated by Pauline Baynes and her work has been retained in many later editions.
  Title: Whale Talk
  Passage: Whale Talk is a 2001 novel by young adult writer Chris Crutcher.  It is narrated in the first person by the quick-witted, sarcastic, and athletic "T.J." Jones, an adopted Asian-African-European-American teenager living in Cutter, Washington, a fictional location in the Pacific Northwest's Inland Empire, set about 50 miles outside of Spokane.  The novel focuses on how T. J. jumbles together a shabby swim team of student underdogs in order to aggravate and shame his high school's elitist athletics program.
  Title: Underland (Narnia)
  Passage: The Underland is a fictional location in the children's fantasy series "The Chronicles of Narnia" by C. S. Lewis.  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.  They find him in Underland and release him from his enchantment by The Lady of the Green Kirtle.
  Title: Wuthering Heights (fictional location)
  Passage: Wuthering Heights is a fictional location in Emily Brontë's novel of the same name.  A dark and unsightly place, it is the focus of much of the hateful moil for which the novel is renowned.  It is most commonly associated with Heathcliff, the novel's primary male protagonist, who, through his devious machinations, eventually comes into ownership both of it and of Thrushcross Grange.  Although the latter is by most accounts a far happier place, Heathcliff chooses to remain in the gloom of the Heights, a home far more amenable to his character.
citations: Underland (Narnia) The Silver Chair