Tollwood is a festival taking place at the start of the first Advent continuing until December 23rd (check the website for exact dates). Its focus is on culture and the environment, and there are a wide variety of programs ranging from live musical and theatrical performances, to speeches and films. The fair-like atmosphere also lends itself to shopping from unique vendors and a bio food court where the focus is on sustainability.
The winter festival is held in the Theresienwiese, the same venue as Oktoberfest. There's also a summer version of the festival held in Olympic Park South.