Niels Klim's Underground Travels

Niels Klim's Underground Travels is a satirical science-fiction/fantasy novel written by the Norwegian-Danish author Ludvig Holberg. It describes the utopian society of Potu, from an outsider's point of view. Assuring the reader that everything is a real account, Klim chronicles the culture of the Potuans, their religion, their way of life and the many different countries located on their planet, Nazar. After being kicked out, he ends up in a land inhabited by sentient monkeys, and after a few years he becomes emperor of the land of Quama, inhabited by the only creatures in the Underworld that look like humans. Originally published in 1741 (in Latin), it is one of the first science fiction novels to use the Hollow Earth concept, as well as one of the first science-fiction novels in history.