EntityQ454943· pop 9· linked from 9 articlesFriedrichstein CastleSign in to savecastle in Russia, formerly East-PrussiaConnectionsWorld War IIConceptSoviet UnionConceptHamburgEntitygeographic coordinate systemEntityBrandenburgEntityRhineland-PalatinateEntityInternational Standard Book NumberEntityKaliningradEntityKaliningrad OblastEntityPrussiaEntityWilhelm IIEntityRed ArmyEntityInternational Standard Serial NumberEntityGestapoEntityPotsdam ConferenceEntityOCLC, Inc.EntityEast PrussiaEntityFrederick I of PrussiaEntity20 July plotEntityKönigsbergEntityCategoriesEast PrussiaFormer palaces