You might want to spend some time browsing the exhibits at LabyrinthUm, Military History Museum of Artillery, or Erarta Museum and Galleries of Contemporary Art. Peter and Paul Fortress, Strelka, and State Hermitage Museum are well-known local landmarks worth a visit. You can watch performances at Alexandrinsky Theatre, Mariinsky Theatre, and Oktyabrskiy Big Concert Hall if you're interested in local theater.