You might want to spend some time browsing the exhibits at Bunker Museum, Kaliningrad Regional Museum of History and Arts, or B-413 Submarine Museum. Some landmarks that you won't want to miss include Ruins of Koenigsberg castle, Timber Bridge, and Honey Bridge. You can catch a show at Kaliningrad Regional Drama Theatre, Kaliningrad Regional Youth Theater for Young Spectators, and Kaliningrad Regional Philharmonic Hall.