You'll want to browse the collections at Bunker Museum, Museum of the World Ocean, and B-413 Submarine Museum. Ruins of Koenigsberg castle, Amber Museum, and Timber Bridge are monuments to see when you're exploring the area around Monument to Karl Marx. You can check out the local talent at Queen Louise Kirsch Puppet Theater, Kaliningrad Regional Musical Theatre, and Kaliningrad Regional Youth Theater for Young Spectators.