Niels Klim's Underground Travels

Niels Klim's Journey Under The Ground. By Louis Holberg, 1741. Tr. John Gierlow. 1845.

Being A Narrative Of His Wonderful Descent To The Subterranean Lands; Together With An Account Of The Sensible Animals And Trees Inhabiting The Planet Nazar And The Firmament 

From the wiki:

Niels Klim's Underground Travels, originally published in Latin as Nicolai Klimii Iter Subterraneum (1741), is a satirical science-fiction/fantasy novel written by the Norwegian-Danish author Ludvig Holberg. His only novel, it describes a utopian society from an outsider's point of view, and often pokes fun at diverse cultural and social topics such as morality, science, sexual equality, religion, governments, and philosophy.