We opted to do a river cruise that night which was fantastic and I highly recommend this to everyone. Singing, Vodka and Caviar. It was a night that we will never forget.
The second day we went to Pushkin (go early) to Catherine's Palace, what a wonderful day this too I would highly recommend, its a must to walk through the gardens.
Port 7 Was Copenhagen - what a wonderful place, friendly historic and we would definitely go back