We are looking into going to Berlin before our river cruise starting in Budapest. How many days do we need to see the main sights?

We first went for five days. We ran out of time to see what we wanted to see and really missed spending a full day to do some of the Potsdam palaces. This past year we did another five days. We've now covered the highlights. Next trip there if we do one we can start adding some "details".

Depending on your interests, I would say five days might be plenty, but three should be the minimum.

On days one and two you might do some sightseeing/ shopping/ and museums in the city. Reserve at least one day for the Sanssouci Palace in nearby Potsdam with its magnificent park.

4-5 days would be a minimum, esp if you want to go out to Potsdam. There are many great museums in Berlin which you don't want to miss out.

Get the book BerlinWalks. It might give you some idea of what you will want to see aside from the museums themselves.