In the Star Trek: The Original Series episode "For the World Is Hollow and I Have Touched the Sky", there is a hollow, artificially created, planet-shaped spaceship whose inhabitants falsely believe that they are living on the surface of a planet. "World Without Stars", the third volume of the French graphic space novel series "Valérian – spatiotemporal agent" takes place mainly inside a hollow planet inhabited by a matriarchal and a patriarchal culture continuously at war with each other. See also Dyson sphere Gravity train Travel to the Earth's center References External links Subterranea Miscellania Stories of a Hollow Earth – article by Peter Fitting on subterranean fiction, including comprehensive links to public domain copies of works – published in The Public Domain Review'', 2011. Adventure fiction Fantasy tropes Historical fiction Speculative fiction