Ekumen Universe

The Ekumen Universe is one of Ursula K. Le Guin's major settings for her science fiction novels. So named for the presence of the Ekumen, a loose, non-governmental body that facilitates trade and communication among the human worlds.

The numerous human worlds allowed Le Guin to create different societies, and even different biologies (see Winter and kemmer).

Other worlds detailed in the books include O, Hain the central world, the sister planets Anarres and Urras, Terra, and Werel and it's system mate Yeowe