Below are places mentioned in the Foundation Series.
“Helicon is a planet in the Arcturus sector of the galaxy. It is part of the Galactic Empire, and...Helicon
“Dahl was a sector of the planet Trantor, which Hari Seldon first encountered during the event...Dahl
“Wye is a sector on the planet Trantor. Like most other Trantorian sectors, it enjoys a certain...Wye
“Mycogen is a sector of the planet Trantor, autonomous like most other sectors, and posessing a...Mycogen
“The Periphery is a name collectively given to the inhabited planets that fall outside the main...Periphery