On our last afternoon in St Petersburg TJ Travel took us to the Peterhof Palace and then a ride back to the city on a hydrofoil.
RCI
Russian and Scandinavia: Second morning in St. Petersburg, Russia
Our second day in St Petersburg started with a river cruise. Then we went to the Hermitage for a long look at the art galleries inside then a walk to cross the Nevsky Prospect. Before we went for lunch we went on the underground and to get there we rode down the deepest escalator in the world.