Casanova's "Icosameron", or, The story of Edward and Elizabeth1986
who spent eighty-one years in the land of the Megamicres, original inhabitants of Protocosmos in the interior of our globe
by Giacomo Casanova
After a shipwreck, Edward and Elizabeth find themselves in the center of the earth and live for eighty-one years with the small humans they find there.
— from OpenLibrary
1 edition at OpenLibrary