Thra is a lush planet and the setting of Jim Henson's 1982 movie The Dark Crystal.
It is located in a trinary star system composed of the Great Sun, the Rose Sun and the Dying Sun, and is home to the eponymous Dark Crystal, the shattering of which was responsible for dividing the urSkek alien race into two distinct races: the monstrous Skeksis and the peaceful urRu.
Native races also include the elf-like Gelflings and the fun-loving Podlings.