This is a unique structure tucked behind the New Rathaus and to the east side. It houses an information cneter and brochures on regional things to do. In addition, there is a video and small museum in the basement, but not much to see/hear; but may have some interest for Duetsch Luete.
It was the imperial residence of Roman emperor Louis IV, with archaelogical proof it existed in the 12th century. It became the residence of Duke of Bavaria in 1255, Louis II, father of Louis IV. The structure was ruined in WWI. but restored, and later some of the facility became apartments.
This had been the residence of the Wittelsbacher, the Bavarian royal family since 1253. Kaiser Ludwig of Bavaria had the official seat there between 1328-1347. The Late-Gothic bay window is also known as 'Affenturm' (monkey tower).