To view possible places to visit you can using links listed below.

Museums:

Hermitage (Whinter palace): http://www.hermitagemuseum.org/html_En/index.html

Russian museum: http://www.rusmuseum.ru/eng/home/

Kunst-kamera museum: http://www.kunstkamera.ru/en/

Summer garden: http://www.rusmuseum.ru/eng/museum/complex/let_sad/

The Mikhailovsky Castle: http://www.rusmuseum.ru/eng/museum/complex/mih_castle/

Cathedrals: http://eng.cathedral.ru/


Theaters (balet, opera):

Mariinsky Theater: http://www.mariinsky.ru/en/

Mikhailovsky theater: http://www.mikhailovsky.ru/en/afisha/

Hermitage theater: http://rus-ballet.com/


Suburb (palaces, parks):

Petergof: http://www.peterhofmuseum.ru/page.php?id=8

Katherine palace: http://eng.tzar.ru/