My daughter (30) and I (60's - but adventurous) will be with Vantage travel company and they are offering several optional tours (for which there is a fee). Can anyone tell me if they are "must sees" or ones we could do on our own? A rivers & canals tour (if it's at night I would want to go because we are there during The White Nights), Pavlovsk, a folkloric show (Cossack songs etc. I think), and Peterhof. Any better suggestions we could do on our own?