The visual impact of the recent renovation works of the Himeji Castle is startling – it used to be thought that the white-plastered walls were the reason why the structure earned it the name Shirasagi-jo or White Heron Castle (aka Egret Castle) – but now that the roofs have been restored to its original gleaming white-tiled roofing, the effect is even more complete, and shows how the regal, elegant and graceful structure must have mesmerized the ancient medieval world.
From the UNESCO World Heritage organization, this is their assessment of the value of Himeji Castle as a World Heritage site …paraphrased below:
Combining an effective functional defense role with great aesthetic appeal, both in the use of white-painted plaster and in the subtle design in the layering of multiple roofs, Himeji castle represents the culmination of Japanese castle architecture in wood.
Himeji-jo is a masterpiece of wooden construction, and the finest surviving example of early 17th-century Japanese castle architecture, preserving all its significant features intact.
The castle is also a powerful and evocative symbol of the feudalism that prevailed for almost three centuries, until the events of 1868 Meiji restoration when the Shogun fell.
The castle property, situated on a hill summit in the central part of the Harima Plain, covers 107 hectares and comprises eighty-two buildings. It is centred on the Tenshu-gun, a complex made up of the donjon, keeps and connecting structures that are part of a highly developed system of defence and ingenious protection devices dating from the beginning of the Shogun period.
Himeji Castle is the largest castle in Japan. It serves as an excellent example of prototypical Japanese castle architecture, containing many of the defensive and architectural features (such as the concentric circular moats, and maze-like approach designed to confound and stall attackers) associated with Japanese castles. Himeji Castle sits ensconsced within concentric moats and walls, and today within extensive grounds that, in its heyday would have contained barracks, stabling, and residences for the lord of the castle’s samurai.
The curved walls of Himeji Castle are sometimes said to resemble giant fans (扇子 sensu), but the principal materials used in the structures are stone and wood. Feudal family crests (紋 mon) are installed throughout the architecture of the building, signifying the various lords that inhabited the castle throughout its history.
By the way, the Himeji Castle is commonly contrasted with Matsumoto Castle, another authentic and non-ferro-concrete structure, which is nick-named the Black Crow Castle(see: Japan Visitor)
Himeji Castle: Design and meaning of its roof By Dr Adrianna Piccinini Nagashino