We took the "beer crawl" excursion in Cologne (our third excursion that day :-)). We had quite a bit of fun as we were bused to an older part of town, then walked to three beer halls, trying the special beer of each. We also had a nice German meal. Along with the camaraderie of our group of about 20 from the boat, we truly enjoyed chatting (in both English and German) with several locals. It was so nice to walk by several hundred, yes, several hundred locals sitting under umbrellas at tables drinking beer, eating snacks, relaxing and talking at the many outdoor cafes we passed while walking. It was refreshing to see them enjoying the evening with friends and family. That Friday night is etched in my memory as that experience wouldn't happen in a large US city today... We were bussed back to the boat at about 10 PM. Our cruise was in June, 2019.
The Bruel Palace tour was very nice as was the walking tour of Cologne. The tour guide of the latter was superb.
We enjoyed our cruise/stay in Amsterdam in 2019 so much that we're off to the Prague/Romantic Danube cruise in July...