Comporellon
Comporellon orbits the star that is known today as Epsilon Eridani. It is the oldest Settler (non-Spacer) world in the Galaxy, as it was the first planet settled by Earth inhabitants during and after the events of "Robots and Empire". It was originally known as Baleyworld, named in honor of Elijah Baley's son Bentley Baley and later became known as Benbally World. This world is known to be very cold and puritanical. Most of the cities, including its capital, are underground. Munn Li Compor's family were originally from this world and remembered the original name of its star, information which led Golan Trevize and Janov Pelorat to visit Comporellon while searching for Earth.
Read more about this topic: List Of Foundation Universe Planets