The notion that subterranean realms exist has found expression in myriad religious belief systems and mythologies. Such underworlds are often places of posthumous spiritual persistence or punishment: for example, Hades in Greek mythology, or Dante’s Inferno, imagined as an inverted conical structure descending deep into the Earth. In 1692, the English astronomer Edmond Halley proposed that the planet itself might be hollow, although he was making a scientific claim rather than a metaphysical one. Various combinations of these spiritual and physical conceits of the Hollow Earth have been expressed in modern fantasy, horror and science-fiction writing ever since.

Image: Illustrated frontispiece for Jules Verne’s from LEs Voyages Extraordinaires (1867-1919, Hetzel Collection, Hachette) Public Domain. Image ©Ex Carta