Japanese Castles of the Houjou: A Field Report
Scribe Figaro
1 March 2008


While in Japan in 2007 I visited three castle ruins of the Late Houjou clan: Odawara (小田原城), Hachiouji (八王子城), and Takiyama (滝山城). 

1.  Introduction


The word for Castle is shiro (城); this character is read as jou when it is the suffix of the name of a castle.

Only a dozen original castles stand in Japan; there exist many ruins which may or may not have excavated or reconstructed features.  These are most commonly called jouseki (城跡) or joushi (城址).

In Japan, as in Europe, castles evolved from a number of defensive structures meant to garrison soldiers and control vital regions.  The essential element of a castle is that it serves as the residence of a regional lord, and the defenses are arranged in a series of rings around this residence to allow defenders to fall back when a line is breached, or when the defenders are too few in number to keep a larger perimeter secure.

2.  Castle design


A Japanese castle uses a series of nested defensive structures arranged in rings ("baileys.")

The innermost bailey of the castle structure is the honmaru (本丸), the castle keep.  This is a flat and open plain, higher than any other in the castle structure, on which the donjon, or main tower, is built.  This structure is called the tenshukaku (天守閣).  The tenshukaku serves as an observation post and a final line of defense.  That the tenshukaku serves as the lord's residence is what makes the castle a castle and not simply a fortress.

Outside the honmaru is a second defensive line, the ninomaru (二の丸).  The ninomaru is arranged so that defenders can attack outward, and so that, if the ninomaru is lost, enemy forces within the ninomaru are extremely vulnerable to attacks from the defenders who have retreated to the honmaru.

Outside the ninomaru is the sannomaru (三の丸) which has a similar relationship to the ninomaru.  The sannomaru is the outermost defensive circle.  The walls and gates of the sannomaru are typically the largest, tallest, and strongest, as they must repel the enemy while he is at full strength.

Additional defensive lines are common.  Within the sannomaru, it is common to have a protected compound (or several) in which the residences of the lord's retainers are kept.  These would be strategically located so that samurai defending these walls would also be able to hinder enemies seeking the honmaru.

Castle design uses natural features whenever possible: steep slopes become walls, ravines and rivers become moats.  Within the sannomaru and ninomaru walls and gates are arranged to confuse and misdirect the enemy, forcing them to spend an inordinate amount of time under fire from the next bailey.  Approaches to gates tend to use walls and moats to constrict the movement of an army: the invading force is physically prevented from amassing in vulnerable areas and funneled toward killing zones.

To withstand siege, the castle would have wells and/or reservoirs for water and vast storerooms to feed the defending army.  Aesthetics were also considered; even the most remote mountain castle made use of gardens of various types.

Not all castles used three concentric defensive circles, but this was the common model and the castles discussed in more detail here are all of this type.

3.  Castle construction


Defensive walls (and most other structures) were mostly constructed with a wattle-and-daub technique on a framework of heavy wooden members.  These were built upon hills with sides protected by a sloped foundation of stones placed without mortar, called ishigaki (石垣) .  These foundations tended to be very stable against earthquakes and resistant to sapping, but on the other hand, the large stones offered handholds which potentially made them easy to scale.  To protect the interior of the walls, they were almost always covered with a sloping roof of shingles.  Often, storerooms called yagura were built into these walls: the additional structure reinforced the wall and made efficient use of building materials.  Many yagura were made into two-story towers on the corner of  a bailey to aid the defense of the wall.

Walls were constructed along hills so that they were taller from the outside than from the inside; from the wall and yagura built into it, many features allowed defenders to observe the enemy and attack with arrows or by dropping rocks, boiling water, or burning-hot sand on anyone attempting to scale them. 

Large gates of iron-reinforced timber were protected by being built into a multi-story structure with a gate at the lower level and a storehouse at the upper level; defenders from above could attack anyone approaching the gate or battering the gate itself.  This was called a yaguramon. The use of yagura as defensive positions was so common that "weapons storehouse" has become an archaic translation for yagura; today it means a lookout tower or any elevated stage.

4.  Types of castles


Mountain castle
(山城 yamajiro)

The earliest castles were built on mountains.  Natural landforms were utilized: steep hills served as walls; ravines served as dry moats; dense woods hampered the approach of large numbers of troops.  The physical building of the castle was minimal: areas would be cleared and flattened for the main tower (if one was built at all) and any other buildings for boarding and storage.  Wooden walls and gates would form barriers against any approach to the castle.

The yamajiro was based on the strategy of being remote and difficult for large numbers of troops or other resources to reach; unfortunately this worked to the defender's disadvantage as well.  They were troublesome to supply and garrison, and they were not visible enough to be very intimidating.  Additionally, many places which needed defending were not near to any mountains.  While a fine defensive position, especially in times of certain war, it was not ideal in all circumstances.

Flatland-mountain castle
(平山城 hirayamajiro)

The flatland-mountain castle was more similar to the motte-and-bailey design of old Europe; a steep hill surrounded by a flat plain was an ideal way to have a commanding 360-degree presence over many miles of land.  These castles could often be located closer to the region it intended to defend, and its design made the movement of supplies and troops easier.  Placing the castle on flatland could potentially make available large supplies of water from rivers and other sources; this made water-filled moats practical and very common.  The most striking aspect was that these castles were visible from great distances and served as strong symbols of a provincial lord's power.

The disadvantage of these castles was that the flatland surrounding the castle could easily serve as staging grounds for a siege, and the comparatively gentle grade made it necessary to place much more effort into building large walls and structures to defend them.

Flatland castle
(平城 hirajiro)

A flatland castle is, quite simply, a castle on a flat plain.  Without naturally sloping terrain, the castle's defenses depended almost entirely on man-made structures.  These castles were often little more than manors with one or more encompassing walls, though if a castle was desired in a place where no hills could be used a flatland castle could be very large.  A major disadvantage of these castles was that their position often made them vulnerable to flooding.

5.  Current state of the Houjou ruins


Takiyama (滝山城址) takiyama joushi

Takiyamajou was a mountain castle constructed in 1521 by Oishi Sadashige, a retainer to the Ogigayats-Uesugi.  His son (?), Oishi Sadahisa, gave birth to only daughters, one of whom married Hojo Ujiteru around 1560 (?).  The Oishi had accepted the Hojo after the Uesugi were expelled from Musashi by the Hojo in 1545; this marriage solidified their fealty - Ujiteru was brother to Ujimasa, the heir of the Hojo clan.  This marriage made Hojo Ujiteru heir to Oishi and lord of Takiyama Castle.

The castle was attacked by Takeda Shingen in 1569 with a force of 20,000 staged on the Tama River plain and advancing straight toward the northern cliff of Takiyama.  Takeda reached nearly to the honmaru but was repelled.  Following this near-defeat, Hojo Ujiteru decided to create a new castle at Hachiouji in 1572.  Takiyama served as a defensive post during and after the construction of Hachiouji; it was finally abandoned in 1587.

Today, Takiyama contains no reconstructed walls or buildings, and though many of the dry moats and earthen walls are still visible, the forest has reclaimed them. Two retainers' compounds still exist as large meadows.  The plateau of the honmaru is connected to another defensive plateau called the nakanomaru (中の丸) by a wooden bridge over a valley.  On the honmaru there exists a small modern shrine building.  From here one can look northeast over the Tama River and floodplain.  The view is commanding in this direction.

Restrooms and a water tap are located in the honnomaru.  There are wooden stands with informational pamphlets and semi-useful maps scattered here and there but nothing in English.  It's a mildly challenging hike (really too easy for my taste) and interesting historically, but I'd suggest passing unless (like me) you were near Tokyo and had nothing to do on a Saturday.

The grounds are not easy to find; I missed several buses and, even after finding the right stop, I had to ask an old Japanese couple for directions.  I threw this together:

Directions: From anywhere in/near Tokyo, take the JR Chuo line (
JR中央) to Hachioji Station (八王子駅, Hachiouji eki).  From here it gets tricky - no English whatsoever.  (Write down or memorize the kanji.)

Take the north exit toward the bus depot and go to bus stop number 14.  From here, board a Nishi Tokyo bus (
西東京) bound for Kyourin University (杏林大学, kyourin daigaku).  杏林大学 will be written on the bus timetable at the stop and on the bus itself; it comes at about 53 minutes past the hour IIRC.  When you see this bus, take a ticket and take a seat, close to the front if you can.  The ride is about 30 minutes or so depending on traffic.

Two or three stops after Kyourin Daigaku is Takiyama joushi (
滝山城址).  Fare is about 470 yen; keep a sharp eye and ear for takiyama joushi and pay attention when the fare screen gets near 300 yen.

If you haven't used a city bus in Japan before, note that you're supposed to pick up a ticket when boarding the bus at the rearmost door, then return that to the pedestal by the driver and pay your fare.  There is a change machine there but it doesn't calculate and take your fare; you have to take the change, count out the exact fare, and put it in the pay slot.  Fun stuff, I know.

Once you get off at the stop, look to your right - across the street - and find a tall white sign with vertical red lettering saying 滝山城址入口, (Entrance to Takiyama Castle Ruins).  You might want to walk backward a little bit; the stop IIRC is 50 or 100 feet past the entrance.  Go straight up a hill past a few houses.  You'll be on a steep paved road.  Once you see the shrine on the right you'll know you're in the right spot.  Continue on and you'll find some maps and information kiosks, all in Japanese.  Have fun!

Hachiouji (八王子城跡) hachiouji jouseki

Hachiouji is a mountain castle constructed by Hojo Ujuteru to replace Takiyama.  The castle is located deeper in the mountains of modern Hachiouji City, and was constructed beginning in 1572.  Hojo Ujiteru began using the new castle in 1584 and abandoned Takiyama completely by 1587.  In 1590, Hojo Ujiteru took much of Hachiouji's forces to defend Odawara from the siege led by Toyotomi Hideyoshi.  Unfortunately, a direct assault on Hachiouji by additional Toyotomi forces came quickly, and lacking its lord, his most loyal retainers, and many of its defenders, Hachiouji fell in a single day.

Little of Hachiouji remains today.  At the base of this castle is a retainer's complex which has been reconstructed; this includes a garden, a bridge, and a wooden fenced area upon sloped stone walls.  This structure lies inside the sannomaru.  (One source says the peacetime palace of the castle lord was placed here.)  The further recesses of the castle are no longer existing except for some stone walls.  Unfortunately, I came to this place too late in the day and wasn't able to get very far up the path before it was too dark to continue.  For that matter, I wasn't all that sure I was on a path anymore.

I got lost as hell on my way to this place so I won't even try with directions.  You are on your own.

Odawara (小田原城跡) odawara jouseki

Odawara is a substantially reconstructed flatland-mountain castle which served as the headquarters of the Hojo clan.  The land was originally the mansion of Dohi Sanehira; the region was captured by Hojo Soun in 1495 and the castle was built here some time thereafter.  Odawara was sieged by the forces of Toyotomi Hideyoshi and Tokugawa Ieyasu in 1590 with a force of 200,000 against 50,000 defenders.  The siege lasted for three months with only a few minor attempts to assault the castle.  During the course of the siege, Toyotomi sent additional forces to major Hojo strongholds.  As most of the Hojo's armies were held up in Odawara, the Hojo received news of its outposts in Shimoda, Oshi, and Yorii falling.  The loss of Hojo Ujiteru's castle of Hachiouji was particularly disheartening.  With supplies dwindling and other vital fortresses already lost, the Hojo surrendered Odawara.  Most of its occupants were spared, though the daimyou and his brother - Hojo Ujimasa and Hojo Ujiteru - were ordered to commit seppuku.

Much of the honnomaru and ninomaru are rebuilt, including very impressive reconstructions of walls, moats, gates, and storerooms. In the ninomaru is a historical museum (Odawarajou Rekishi Kenbunkan); the clerk working there was nice and appreciated my Chicago Cubs hat, but the material in the museum was almost entirely text and audio/video presentations of information one could more easily find elsewhere.  Outside this museum is a large gravel area where flea markets are held many Sunday afternoons.  Inside the honmaru is a small zoo with Japanese macaque.  The main tower is a fair exterior reconstruction; its interior is a decent museum, containing (among other artifacts) a number of swords of the Masamune school.  The ubiquitous gift shop and shrine is located at the top floor. 

The gates to the ninomaru show impressive castle design in a style common for flatland-mountain castles. The main path into the castle is at the lower left of this map. The first solid line of defense is a water-filled moat that completely surrounds the castle. Breaching the sannomaru requires an army first spend time on a small island in the moat. They must breach a gate ahead of them, then turn left and breach another gate to access a garden. The edges of the island are sharp and steep, with no walls, so if the enemy crowds the area many will be knocked into the water. The area between these two gates is exposed to arrows from a corner tower across the moat.

After breaching the second gate and entering the garden, the army must turn right and go straight. To the right is a narrow bridge that passes over the moat and funnels the army into a small gate. Breaching this gate leads them into a rectangular walled-in killing zone. To the invaders' left is a yaguramon at the top of a steep grade, from which defenders can fire arrows. There is almost no cover for the invaders, and the small gate and narrow bridge make it very difficult for them to retreat. The gate itself is the strongest in the castle complex; this is intended to be the defenders' most powerful position.

Should the invaders pass this gate and breach the ninomaru, they are faced with a steep climb to the honmaru, which includes another moat bridge. The main gate is to the right side of a walled alcove in the honmaru line, allowing defenders to shoot at the invaders below from three different sides.

Finally, the tower. If the battle should reach this far, the defenders have little chance and surrender is almost guaranteed.

The tower requires a 400 yen ticket and the tower and Rekishi Kenbunkan can be purchased together for 600 yen; having done so I think the Rekishi Kenbunkan is not worth the additional 200 yen.

Maps and informational placards in Japanese and English are numerous and restroom facilities are easily located but of typical park quality.  A very popular tourist spot.  If you're feeling adventurous, after dark turn right from the front gate of the castle and look down the sidestreets for a most excellent unagi shop.  (Directions to follow when I find them.) In addition, Odawara is very near the very popular baths of Hakone.

Odawara Castle is a 10 minute walk from Odawara Station; it is visible from the station and signs on the major roads will direct you. Odawara Station is about 90 minutes and (as of 2007) 1450 yen from Tokyo Station on the Tokaido Line. There are better castles in Japan, but if you're in Tokyo and can't justify a 2+ hour Shinkansen, Odawara is a very good day trip.

6.  Glossary


6.1 Castle features
石垣        ishigaki, stone wall
土塁        doroi, earthen wall
堀            hori, moat
空堀        karabori, dry moat
溜池        tamaite, reservior

城            jou, shiro, castle
城跡        jouseki, castle ruin
城址         joushi, castle ruin

天守閣        tenshukaku, main tower
天守            tenshu, main tower
本丸            honmaru, main bailey
二の丸         ninomaru, second bailey
三の丸         sannomaru, third bailey
家臣屋敷   kashin yashiki, residence for retainers
門  mon, gate
矢倉門, 櫓門   yaguramon, large gate with defensive position above


山城               yamajiro, mountain castle
平山城            hirayamajiro, flatland-mountain castle
平城               hirajiro, flatland castle

6.2 Place names

武蔵   Musashi
江戸城      Edo Castle
小田原城  Odawara Castle
鉢形城      Hachigata Castle
川越城      Kawagoe Castle
松山城  Matsuyama Castle
韮山城  Nirayama Castle

7.  Images

Takiyama Castle
Hachiouji Castle
Odawara Castle



Takiyama map glossary
多摩川   tamagawa, Tama River
土塁        doroi, earthen wall
空堀        karabori, dry moat
溜池        tamaite, pond
園地             enchi, garden
家臣屋敷   kashin yashiki, residence for retainers



7.  References

Guide to Japanese Castles
Jim Breen's WWWJDIC Japanese Dictionary Server
Shiro: A Japanese Castle
A Brief History of the Castles of the Oishi Clan in Western Tokyo

Anime Music Video
Fanfiction Resources
Scribe Figaro
Hagakure Productions