Cologne in one day, Monday?

Here's a fairly recent thread with ideas (and very useful links) of what to do when you're in Cologne and only have a limited amount of time. You may take those two museums mentioned in that thread as a backup in case weather doesn't permit something more interesting, I certainly wouldn't call them 'musts' (in fact, I hardly call anything a 'must' at all...).

Note that you can very easily stroll from the cathedral across the railway-bridge to the other riverside for a nice panoramic view.

As you cannot visit all 12 romanesque churches, it's indeed a good idea to select, yet there is no 'ranking order' among these churches, it depends a lot on personal taste (my favourite is Maria im Kapitol ).

I know that everything in Europe closes on Monday (Vienna doesn't even have many shops open on Monday, if you can believe that), but perhaps the Chocolate Museum will still be open. We enjoyed that. It was better than I expected.

It's a shame but not surprising that the other museums are closed. Cologne has some nice art museums.

Chocolate Museum is also closed on Mondays. Not aware of a major museum in Cologne open on Mondays.

Thanks for your answers, especially Nautiker's link to a previous thread has provided lots of info.