[nameless]
A small, isolated planet. Life is sparse, terrain is rocky; the planet was a human interstellar colony, now abandoned by the Earth fleet and left adrift for thousands of years. The descendants of the colonists believe themselves to be natives of this planet, and the sole intelligent species on it, but they are wrong. It has its own native life forms who are aware of the colonials. The laws of physics apply, albeit with concession for unknown cosmic phenomena; such phenomena would have an internal logic, but not one we are familiar with or that we can understand.
The story set herein may not necessarily even allude to these facts, since I would frame the story as folklore, with the colonials believing they "walked out of the sky" and were given this world to live in.