GD

The GD is short for Gräfin-Dönhoff-Gebäude which is German. The Gräfin-Dönhoff-Gebäude (English: Countess-Dönhoff-building) is one of the buildings of the university campus and contains a lot of lecture halls and the mensa.

If you want to get to know more about the woman the building was named after, click here: https://en.wikipedia.org/wiki/Marion_Dönhoff