I have already been to St Petersburg during my Moscow days and hence didn't plan a visit to the Hermitage.
We started the day with a trip to Peterhof. The Hydrofoil started at Hermitage and lasted 30 minutes and we were in Peterhof. The Peterhof Palace (Russian: Петерго́ф, (Dutch for Peter's Court) is a series of palaces and gardens located in Petergof, Saint Petersburg, Russia, laid out on the orders of Peter the Great. These palaces and gardens are sometimes referred as the "Russian Versailles". This is recognized as a UNESCO World Heritage Site.
The garden is huge and very beautiful. There's a bus ride for 30 mins giving highlights of the garden. You can understand the size. It is beautiful and has many lovely trees and bushes. Next we entered the palace and it is stunning. The palace was left in ruins by the Germans during WWII and it is amazing to see it back in full splendour. We took the Hydrofoil and headed back to the city.
Serbian fish and meat place, highly recommended, was our next stop. Was it lunch or dinner, if one were to eat at 4pm. Who cares??
Now that we were refreshed church of the savior on blood was next stop. The church is stunning and is right next the Main Street - Nevsky Prospekt.
Walked a bit around the beautiful city and tired but satisfied we were off to bed.