a tavern below street level featuring beer; originally a German restaurant in the basement of city hall
[German Ratskeller, Rathskeller, restaurant in the city hall basement : German Rat, council, counsel (from Middle High German rt, from Old High German. See ar- in Indo-European Roots) + German Keller, cellar (from Middle High German, from Old High German kellri, from Latin cellrium. See cellar).]
I love that Germans have a word for where they go to get drunk in between bouts of governing.