A novel is a relatively long work of narrative prose fiction, typically published as a book. The English word derives from the Italian: novella for "new", "news", or "short story of something new". A novella is a short novel, whose length is shorter than that of most novels, but longer than most short stories. And for centuries there have been stories set in caves or other underground places.
In the 19th century, a completely new form of literature emerges, the historical novel or historical fiction. There are numerous references to caves in this kind of literature, often a result of romantic misconceptions. A special form are the so-called Stone Age novels. Here an attempt was made to convey prehistoric events in the form of a fictional plot. While the literary form of historical novels rose to prominence in England with novels like Ivanhoe, the Stone Age novels are a German invention. The first such novel was by Christian David Friedrich Weinland in 1876 and is called Rulaman. Much more famous, of course, are the Ayla books by archaeologist Jean M. Auel, the first volume was even made into a film with Daryl Hannah.