You might want to spend some time browsing the exhibits at Bunker Museum, Museum of the World Ocean, or B-413 Submarine Museum. Ruins of Koenigsberg castle, Timber Bridge, and Amber Museum are well-known local landmarks worth a visit. You can watch performances at Kaliningrad Regional Drama Theatre, Kaliningrad Regional Youth Theater for Young Spectators, and Queen Louise Kirsch Puppet Theater if you're interested in local theater.