You might want to spend some time browsing the exhibits at C-189 Submarine Museum, Russian Vodka Museum, or Erarta Museum and Galleries of Contemporary Art. Saint Petersburg Conservatory, St. Nicholas' Naval Cathedral, and Yusupov Palace are well-known local landmarks worth a visit. You can watch performances at Mariinsky Theatre, Rimsky-Korsakov Conservatory, and Alexandrinsky Theatre if you're interested in local theater.