We landed in London and spent a day before going to the conference in Bonn. Then on a whim, we went to Amsterdam for a week.
Amsterdam has beautiful canals all through the city and suburbs, and there are many parks. Bicycles are everywhere, dozens everywhere, parked, in use, everywhere you see, in part because there are special bike lanes everywhere as well. It's pretty chaotic - like polite anarchism - getting around. We rented bikes for 4 days and had a great time cycling around. We stayed for 2 nights downtown at a "cheap" hotel (70 euros, but that's cheap for there), then we moved to a suburban campground for about 16 euros/night. The "coffee shops" are still open to tourists, so we had a lot of fun. We stayed away from the tourist traps and had a great time hanging out. Friendly people at the bars, getting lost until 3 am on our bikes - nothing gets us down!