Novgorod

Novgorod was Russian capital in the old times and its historical city center is quite nice although should I be honest I wouldn't recommend anyone to stay there overnight because there's not much to do.....Couple of hours, max one day is enough. The most impressive thing there was the Monument to the Millenium of Russia (http://en.wikipedia.org/wiki/Millennium_of_Russia).

Transport costs: Bus Petersburg-Novgorod 360rub, overnight train Novgorod-Moscow (860rub, 3rd class - hard sleeper)