Stone bases, white walls and winding ways in
How a castle was built to keep attackers out, from the moat to the top floor of the keep.
Jump to: Mountain, hill or flatland | The keep | Walls and plaster | Keeping attackers out | Foundations | Roof ornaments | Inside the walls
Mountain, hill or flatland
Himeji-jo stands on a hill summit in the middle of the Harima Plain. UNESCO World Heritage Centre: Himeji-jo Matsumoto is a flatland castle, built on flat ground 590 metres above sea level. Matsumoto Castle official website: The Keep and Its Structure
Hirosaki Castle is built on a flat plain, unlike many castles on high ground. JNTO: Hirosaki Castle
Bitchu Matsuyama stands on a 430-metre mountaintop, the highest fortress in Japan with a surviving castle tower. JNTO: Castles in Japan (Tourist Information Center leaflet, April 2024)
Matsuyama Castle sits on top of Mt. Katsuyama and can be reached by ropeway, chairlift or on foot. JNTO: Discover Japan’s Twelve Original Castles
Inuyama Castle looks out over the Kiso River. JNTO: Inuyama Castle Hikone looks out over Lake Biwa, Japan’s largest lake. JNTO: Hikone Castle
The keep
At its centre is the Tenshu-gun: the donjon, keeps and the structures that connect them. UNESCO World Heritage Centre: Himeji-jo
The floors of the keep get smaller as you climb, and the top floor has a small shrine. JNTO: Himeji Castle The keep stands 32 metres high, on the top of Mt. Himeyama. JNTO: Himeji Castle (UNESCO)
Matsumoto Castle is the oldest surviving castle with five stories outside but six floors inside. Matsumoto Castle official website: About Matsumoto Castle The main tower looks like 3 levels from outside, but has 6 floors and a basement. Kumamoto Castle official website: About Kumamoto Castle
From outside it looks like five storeys, but inside there are eight floors, including a basement. Japan Tourism Agency: Osaka Castle Main Tower The tower is 58 metres tall and made of steel and concrete, on the old stone base. Japan Tourism Agency: Osaka Castle Main Tower
The south-west corner watchtower looks two storeys high from outside but has three floors. Nagoya Castle official website: Nagoya Castle
Uto-Yagura has 3 tiers, 5 storeys and a basement, and is called the Third Tower. Kumamoto Castle official website: About Kumamoto Castle
Matsumoto is the only castle in Japan where a “linked keep” and a “compound keep” can be seen together. Japan Tourism Agency: Key Features of Matsumoto Castle
Nagoya’s great keep had the greatest floor space of any keep ever, says the castle’s website. Nagoya Castle official website: Nagoya Castle
Walls and plaster
UNESCO calls it a masterpiece of construction in wood. UNESCO World Heritage Centre: Himeji-jo The thick white plaster resists fire and bullets. JNTO: Himeji Castle (UNESCO)
Its white plastered earthen walls have earned it the name Shirasagi-jo, White Heron Castle. UNESCO World Heritage Centre: Himeji-jo
JNTO describes Kumamoto’s imposing black outside and steep ramparts. JNTO: Kumamoto Castle Matsue is also called the Plover Castle, because of its shape and black outside. JNTO: Matsue Castle
The walls on the first and second floors are about 29 centimetres thick. Matsumoto Castle official website: The Keep and Its Structure
Kumamoto’s curved stone walls are called musha-gaeshi, roughly “warrior repellent”: the higher you climb, the steeper they get. Kumamoto Castle official website: History The castle’s website says even nimble ninjas failed to climb the walls. Kumamoto Castle official website: History
Iron spikes called shinobi-gaeshi once topped the stone wall of the small tower. Kumamoto Castle official website: About Kumamoto Castle
The Nagabei Long Wall runs in a straight 242-metre line along the Tsuboi River. Kumamoto Castle official website: About Kumamoto Castle
Keeping attackers out
The castle was built for war, with 115 gun and arrow slots. Matsumoto Castle official website: The Keep and Its Structure The Japan Tourism Agency describes 115 loopholes and 11 ishi otoshi openings over the stone base. Japan Tourism Agency: Key Features of Matsumoto Castle
There are 11 openings in the first-floor wall where guns could shoot downwards. Matsumoto Castle official website: The Keep and Its Structure
There were openings in the walls to shoot from, and windows for dropping big stones on attackers. JNTO: Himeji Castle (UNESCO) The corner watchtowers have ishi-otoshi: stone-dropping chutes above the walls. Nagoya Castle official website: Nagoya Castle
Hikone has a spiral ramp to the entrance that made attackers easy targets, and hidden openings for archers. JNTO: Hikone Castle
Winding, maze-like passages were meant to confuse attackers and keep them from the keep. JNTO: Himeji Castle (UNESCO)
The inner moat is 60 metres away, which matched the longest accurate range of a matchlock gun. Matsumoto Castle official website: The Keep and Its Structure The inner moat is about 60 metres across: the furthest a matchlock would reliably pierce samurai armour. Japan Tourism Agency: Key Features of Matsumoto Castle
Samurai lived inside the triple moat, which made the defences stronger. Matsumoto Castle official website: The Keep and Its Structure Only one of Himeji’s three original moats survives intact. JNTO: Himeji Castle
Foundations
The castle weighs about 1,000 tonnes and stands on soft ground. Matsumoto Castle official website: The Keep and Its Structure Inside the stone base are hemlock logs, 5 metres long, that help carry the weight. Matsumoto Castle official website: The Keep and Its Structure
The Japan Tourism Agency says the foundation used 16 hemlock posts in a four-by-four grid. Japan Tourism Agency: Key Features of Matsumoto Castle
Under the moat, a raft of logs stops the stone wall sinking into the soil. Matsumoto Castle official website: The Keep and Its Structure The stone walls of the keep have been repaired but not rebuilt since they were first stacked 400 years ago. Matsumoto Castle official website: The Keep and Its Structure
The only modern intrusion is a reinforced concrete foundation raft, added because the soft ground was deforming the buildings. UNESCO World Heritage Centre: Himeji-jo
Roof ornaments
The keep is topped with golden shachihoko: tiger-fish roof ornaments. Nagoya Castle official website: Nagoya Castle The golden ornaments were restored in 1959. The male one is 2.621 metres tall and weighs 1,272 kg; the female is 2.579 metres and 1,215 kg. Nagoya Castle official website: Nagoya Castle
The scales of both golden ornaments are covered in 18 carat gold. Nagoya Castle official website: Nagoya Castle
Inside the walls
A kitchen in the inner court was ready in case of a siege. JNTO: Himeji Castle (UNESCO) Matsue has the only surviving castle keep with a well inside. JNTO: Matsue Castle
Rooms in the tower are still named for the weapons once kept there: the gun room, the armour room and the arrow room. Kumamoto Castle official website: About Kumamoto Castle
Under the Honmaru Goten palace is the Kuragari-Tsuro, a dark stone passage, and the palace’s official entrance is underground. Kumamoto Castle official website: About Kumamoto Castle
Akazu-no-mon, the north-east gate, was not usually opened: in Japanese culture the north-east was thought unlucky. Kumamoto Castle official website: About Kumamoto Castle
The Hommaru Palace has 13 buildings with over 30 rooms, covering 3,100 square metres. Nagoya Castle official website: About the Hommaru Palace The lord’s audience room sits higher than the other rooms, as a show of authority. Nagoya Castle official website: About the Hommaru Palace
The palace rebuild drew on 1,047 surviving Edo-period sliding doors, screens and panels, 309 drawings and 700 photographs. Nagoya Castle official website: About the Hommaru Palace
Our sources give dates and totals in different ways, and some disagree by a year or count different groups of towers. We copy each figure as its source gives it, rather than converting, so every figure matches its link. Every fact was checked against its source on the date shown on the sources page. See when sources disagree for the open questions side by side.
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