The highlight of the Cruise for me so far would have to be Tallinn - about which I knew almost nothing. But the "Old Town" here is an exquisite Medieval Town with turreted walls and medieval houses, churches, restaurants and even a Pharmacy that has been continuously operating since the Middle Ages. The streets are cobbled and wander aimlessly in all directions like old goat tracks. There was not enough time to see it all, and I would put it on my list of "must returns".
We also saw a beautiful ruined abbey - a Birgitta abbey (which I guess is Brigidine). Now it's an empty shell and a rock band was setting up inside it for a concert. Wasn't Bridget a patron saint of music? Or is that Cecilia? Never mind, it didn't seem incongruous!
The next four days are in ports - 2 days in St Petersburg, 1 in Helsinki and 1 in Stockholm. Not enough time for anything more than a nibble at these places.