Hari Seldon, the fictional, intellectual hero of Isaac Asimov's Foundation Series, First Minister of the Galactic Empire.
A fretum is a strait of liquid connecting two larger areas of liquid. On Titan they are named after characters from the Foundation series of science fiction novels by American author Isaac Asimov (1920-1992).
Image Source. Marker locations are approximate and may not always appear to align with image on map.