Bonn was the birthplace of Beethoven and the former capital of West Germany. Köln (Cologne in English) is a big city and has lots to do and see, including a really cool-looking Cathedral. Wikipedia says it was founded by the Romans in 38 BC!!! By contrast, Barrie was first settled in the early 1800s! So that's 1800 extra years of awesome Cologne has on Barrie. Also, there is no hideous spirit catcher statue, presumably.
It'll be in the West of Germany, so France, Belgium, and the Netherlands aren't far away, not that plane tickets seem all that expensive anyway! Another huge city, Düsseldorf, isn't far away either. Basically, it's gonna be awesome.
I plan to book my plane tickets this Sunday, aiming for the beginning of June!