Judy,
Isn't river cruising wonderful? We did Bucharest to Amsterdam last year & loved it. Next week we do the the Duoro River in Portugal.
We spent 4 days in Berlin in freezing March weather prior to a WWII trip. We visited a concentration camp just outside Berlin which was used as their training ground for all other camps abd we took a Communist walking tour visiting Stassi sites, the wall, KGB building & checkpoint Charlie. We also took a walking Nazi tour. We also saw many of their most famous landmarks & museums. It is an easy city to get around in (in March) & we really enjoyed ourselves.
Regards, Jackie