The Park of Peterhof is roughly split into two parts. The Upper Gardens are a formal collection of pools with small fountains in, flower beds and hedges in shapes reminiscent of the French imperial style. The good thing about this side is that it is free, although as you move into the Lower (Nizhny) Park (for which you have to pay for) you will soon understand what you have just seen is actually quite unimpressive.
The Lower Park is where all the big extravagant fountains are as well as numerous small museums and pavilions, cafes, ice-cream stands and yes, it has to be said, in summer time the place is chock-a-block with tourists. If you want to escape from the crowds, head all the way down to the gulf of Finland and follow the rocky beaches up in either direction. You'll soon find that the crowds (and spectacular sites) peter out as you enter more dense parkland and forest.