The Honmaru Palace within Nagoya Castle's main bailey is the most ambitious traditional-architecture reconstruction in postwar Japan. The original — built in 1615 as the official residence and audience hall for the lords of Owari domain — was destroyed in the 1945 firebombing along with the keep. Reconstruction began in 2009 using surviving prewar measurements, photographs and material samples, and finished in 2018 at a cost of around 15 billion yen.
The result is jaw-dropping. The Genkan entrance hall opens into a sequence of audience chambers, each more elaborate than the last, with gold-leaf walls, painted screens of cranes, tigers and rocky shores, and intricately carved transoms above the lintels. The Jorakuden — the apartments reserved for visiting Tokugawa shoguns — is the climax: deep gold ceilings, lacquer detailing, and the cypress beams left bare so visitors can see the carpentry. The palace is included in the castle admission and is open daily.