Knollgraben
Knollgraben is a water body name:
- Knollgraben (Ach) , left tributary of the Ach (to the Ammer) in the Schönberg von Rottenbuch district, Weilheim-Schongau district, Bavaria
- Knollgraben (Brookwetterung) , right tributary of the Brookwetterung in Escheburg , Duchy of Lauenburg district, Schleswig-Holstein