Great port to visit. Tour provided by Viking was very informative and just the right length of time. Passau had a smaller Christmas Market than some of the other ports but the shops themselves were very high end with great inventory. The streets were primarily cobblestone so people who had mobility issues would have difficulty traversing the city.
Very interesting port. City has great architecture. The tour was very informative and interesting. The Christmas Market was good although the day we were there it was raining the whole afternoon. The city would definitely be worth having more time than the one day visit.