We walked around the outside of the university in Bonn, enjoying one of the few green spaces in the city.
We also visited 2 museums - the very excellent German history museum in Bonn and a special exhibition on space exploration at the art museum. First the German history museum, which covers, basically, from WWII to present day. The museum begins with the Holocaust and then moves into the post-war period. There was a reproduction of a newspaper with graphic pictures from the Holocaust and the headline: "This disgraceful deed: your debt." I'm not including the photo here, as it's quite disturbing.
This picture is from a display of the reconstruction that happened in the first ten years after the war, showing a number of cities (this one is Kassel). Most of the reconstruction was done by women, children, and old men, given that men of fighting age were either dead or, at least in the period immediately after the war, in POW camps.
The story of the Berlin airlift is a great tale. (Daring Young Men: The Heroism and Triumph of The Berlin Airlift-June 1948-May 1949 is a good account of it if you're interested.) They were often called "raisin bombers" for the very popular boxes of raisins they dropped, and this is a model someone made of one from raisins.
I didn't take any pictures of the space exhibition (I would've gotten Darth Vader if pictures were allowed) but it was an odd mix of history and technology with art and fantasy. They were combined in a way not typical of American museums. My favorite part was a wooden sphere that you could crawl into, and then could see the northern and southern hemisphere constellations via tiny holes in the wood.
We also came upon a demonstration in front of the city hall of Bonn. It had to do with keeping a particular school open.