Nishaya
Part of the pre-Imperial Kingdom of Trantor, Nishaya is mentioned in Forward the Foundation. At the end of the Empire it was noted for its goat herding and high-quality cheeses. Laskin Joranum pretended to be from Nishaya during his campaign to overthrow Eto Demerzel. What gave him away to Hari Seldon was his perfect mastery of the Trantorian dialect; real Nishayans spoke a very different dialect of Galactic Standard.
Read more about this topic: List Of Foundation Universe Planets