Long 2 days but well worth being a bit tired. Booked through Celebrity because I was a little nervous about customs and visas. It was a 1.5 day tour. That was enough. Some people booked the 2 day. I could not imagine. So we got to see the main sites
Peter and Paul fortress, Hermitage museum, St. Isaac's and Church of spilled blood on the first day. The second day we visited the gardens of Peterhof. We were lucky it called for rain but it held off until we were almost through. Lunch was provided in a great restaurant called Biblotique on the main shopping street. It consisted of borst, salad, stroganoff, apple cake and coffee. Be very careful in Russia. One of our fellow bus mates had their wallet stolen right outside of the restaurant while waiting for the bus. Luckily he was really high tech and able to cancel his cards and only had minimal money in his wallet.
Read sunfish8's full Celebrity Silhouette cruise review