|Description||Castle features that can be found at this castle site|
There aren't any original bridges left but there are a few that have been faithfully reconstructed. This category covers those as well as those that were simply erected for convenience.
During the Sengoku Period the importance of castles grew as military and government functions became centralized around them. The castle town was viewed as an extension of the castle's defenses. The roads surrounding it are a maze of dead ends, T-junctions, and narrow winding streets. With the increasing administrative role of castles they also became the economic center of the province. Vassals moved their personal quarters near the castles, peasants, artisans and businessmen soon followed and the successive expansion of these castle towns led to what are some of the largest cities in Japan today. Much of the layout and planning of Tokyo was designed by the Tokugawa to be built around the castle.
The classification of "castle town" is subjective. Many more castles had castle towns than what have been tagged here. I only tagged castles where there are sufficient remnants to give you some atmosphere of a castle town. If you think others should be tagged likewise, please let me know.
There are many different types of gates, but the basic construction is the same for all. Two columns (kagamibashira) that hold the gate doors are connected by a crossbeam (kabuki) across the top. Usually, the columns are joined to support pillars (hikaebashira) behind them to help prevent the gate from being pushed over backwards. The rest of the gate construction is developed from the gate's position, function and defensive needs.
Gates were often strategically positioned in the walls of each bailey so that anyone who attempts to enter the castle must zig zag back and forth to reach the inner grounds and the main keep. Gates were often further fortified by bolting metal plates over them for strength.
A gate with a yagura situated on top. These are often large, strong and impressive looking gates. They are frequently used as the inner gate of a masugata and for other important entrance points. Yaguramon were were a safe place to observe the outside and they could be used as defensive platforms with defenders in the top. They were equipped with loopholes and windows to shoot from and the floor in front of the gate could be opened like a rock chute to attack anyone at the doors below. There are 2 types of yaguramon. Watariyagura style uses a watariyagura to span from one stone wall across the gate to another stone wall. The other style is basically a free standing yagura with a gate built into the first floor.
Free Standing Yagura Gates
A gate where one roof covers both the main front pillars (kagamibashira) and the rear support pillars (hikaebashira). The roof was necessarily large to cover all four pillars. This is an older style gate that was eventually replaced by Koraimon gates (see below), because it was impractical for defense. The large roof blocked the defenders vision of the outside and it actually shielded any attackers at the doors. There are very few extant examples of yakuimon gates at castles today. The second picture below is an inside view of the gate in the first picture so that you can get a better view of the structure of Yakuimon gates compared to Koraimon gates. The picture from Kakunodate Castle shows a smaller yakuimon in front of a samurai home.
The front pillars and doors are covered with one small roof and the rear support pillars and support beams are each covered by a separate roof on either side at right angles to the main roof over the front pillars. This type of gate is often used as the outer gate of a masugata. There are two types of Koraimon. The roof of the older style is nearly even with the surrounding walls, while the newer style gate is taller so the roof is up higher than the surrounding walls.
Older Style Koraimon
Newer Style Koraimon
Munamon is a gate with two main pillars covered by a roof. It is similar to the koraimon, but lacks the extra support pillars in the rear making it relatively unstable. It is often wedged in between stone or earthen walls to gain extra support.
As the name implies, tonashimon is literally a gate with no doors. The only extant gate of this type that I know of is at Iyo Matsuyama Castle. It is basically a koriamon gate with no doors. It is said that this gate was built here atop a long slope at the front of a hairpin curve to trick attackers into thinking it would be an easy way into the castle. Once they pass through the gate and around the curve they are actually met with a large heavily fortified gate.
This is a gate with only the two front vertical pillars and the one horizontal cross beam. It has doors but no roof. This gate is a formality only and has little or no defensive value.
A heijuumon gate takes the kabukimon a step further and eliminates the cross beam between the two front pillars.
This is where a gate is passed through a section of a long warehouse. Rooms were easily built on either side of the gate and it was often used as a guardhouse around samurai homes.
An ornate gate with a karahafu style roof. A karahafu is a gable chracterized by the rounded ridge in the center. There are several surviving karamon that were moved from castles to temples, but the only one that I know of that is at a castle is the famous gate from Nijo Castle.
Uzumimon literally means buried gate. There are two types of uzumimon. In one type, a hole is literally cut through the middle of a completed stone wall. In the second type, when the stone walls are constructed a narrow gap is left for a gate. Then the defensive wall atop the stone wall foundation is run across the gate evenly with the rest. An uzumimon was often used as an emergency exit or as a rear entrance to the castle.
A masugata is a compound gate made up of 2 gates, most commonly a koraimon on the outside and a yaguramon on the inside. The 2 gates are placed at right angles and joined by walls to create a square enclosure. Any enemy who attempts to enter the castle will be trapped in the box while it tries to breach the strong inner gate. The trapped enemy is then vulnerable to attack from the defenders inside the castle, and lining the walls above.
The large tower seen in many pictures of castles is the main keep. It is nestled in the most central courtyard among the maze of moats, walls, gates and courtyards that make up a castle. The main keep is not the castle itself. It is only one part of the castle. In fact, not all castles even had a main keep. Many early castles or mountaintop castles did not have one. When a main keep was burned down by fire or destroyed in an earthquake, it was sometimes not rebuilt. This is because during the relatively peaceful times of the Edo Period the main keep was less important than earlier times, the costs may have been too prohibitive or in some cases the Tokugawa government simply wouldn't give permission to a lord to rebuild the main keep. During the Edo Period, lords were required to get approval for any major improvements to their castles.
Main keeps were built on top of a high stone foundation or along the top of the stone wall on the edge of the bailey. Like all Japanese architecture, castles relied heavily on wooden construction. This made them much more vulnerable to fire and artillery than the stone keeps of European castles. The exterior walls of most main keeps, as well as other castle fortifications, were covered with thick layers of plaster for protection from fire and artillery. Even so, a great many castles have burned to the ground from fires caused by earthquakes, lightning or attack. The fear of fire was so prevalent that killer whale talismans (shachi) were mounted on top of all main keep and many other fortifications to protect them from fire.
Main keeps can be classified by two major methods, the architectural structure and the style of the main keep. It's difficult to explain some of the concepts with words or with the pictures I have, so I created some basic Google Sketchup diagrams that you can see for each subcategory below. These are intended to be simple visual aids and not perfect scale reproductions.
There are two architectural structure types for main keep: sotogata and borogata. It is usually fairly easy to distinguish between the two. Borogata has an irimoya gable (see the starred part of the picture below) and it looks like the lower floor(s) and the upper floor(s) are of different styles, with the upper floors being square. If not, it is sotogata.
Borogata literally means "lookout tower type." This is the older type of main keep built when the techniques for building stone foundations were less advanced. It is built on an irregular shaped stone foundation that is not perfectly square. An irimoya style gabled roof is used on the first or second floor to provide a roof for the lower levels of the main keep. A square shape is created in the middle of this roof on which the upper levels of the main keep are built. The upper levels are square and balanced. It should give the impression of a lookout tower mounted atop another building. Here are some representative Borogata type main keep. Aya Castle, in particular, exemplifies the look of a watchtower built atop another building.
Sotogata literally means multi-leveled tower type. This type of main keep is built when the foundation is nearly square. Each level is the same shape, simply a little smaller than the previous. You will not see any irimoya gables on a sotogata type main keep. The smaller gables you do see on sotogata main keeps are primarily decorative and are not a necessary part of the roofing construction of the castle.
Main keeps rarely stood alone and were often attached to smaller sections of yagura, small keeps, or large gates or walls to strengthen their defense. How they are connected to other structures determines the main keep style.
Compound - Fukugoshiki (複合式)
The main keep is directly connected to a smaller tower or yagura.
Adjoined - Renketsushiki (連結式)=
The main keep is connected to a smaller tower or yagura by a watari-yagura. I picked Matsumoto Castle below as one example of a renketsushiki main keep, but actually Matsumoto Castle exemplifies both Fukugoshiki and Renketsushiki. The Inui Kotenshu is connected by a watari yagura, making it renketsushiki, but the Tatsumi Tsuki-yagura on the opposite side is connected directly to the castle making it fukugoshiki.
Complex - Renritsushiki (連立式)
The main keep and multiple smaller tower/yagura are each connected by watari-yagura or tamon yagura to completely enclose a small courtyard or the entire honmaru bailey.
Independent - Dokuritsushiki (独立式)
The main keep stands independently of other yagura.
Dwellings in the castle towns were highly regulated by the local lord. Particularly during the Edo Period with the fixed caste system instituted by the Tokugawa, all samurai kept their permanent home near the castle. These samurai quarters are called Bukeyashiki or Samuraiyashiki. In the samurai quarters, the proximity to the castle and the size of the home were respective to the samurai's rank and standing with his lord. Samurai homes were typically modest dwellings but with the significant distinction that only samurai houses were allowed to have walls and gates. Samurai residences were technically the property of the local lord so he could change the residence or rank of the samurai at will.
Ishigaki are one of the most impressive features of any castle. The skill it took to make them from cutting and collecting the stones to actually building the walls in a myriad of shapes, terrains, and locations, is truly remarkable. The fact that there are still so many stone walls remaining after hundreds of years attests to the skill of their builders too. You can even read the history of a castle from its ishigaki. The type of stone tells you where it came from, markings on the stones tell you who it was cut or gathered for, and the method of building the walls can also tell you in what period they were constructed or by whom. Even in the same castle, you may see walls constructed with different methods indicating who built them and when. You can also find unique stories buried in the stone walls at many castles like the old woman who donated her grinding stone or Buddhist statues that were procured from temples to fill in the walls.
Below is a description of the main styles and types of stone walls. There are also a few sub-categories and rare types not discussed here that I may put together for a future page.
The pictures below are from a display at Kanazawa Castle that show how the stone walls are constructed. You can see that the stones are much longer and larger than they appear from the outside. Smaller stones are filled in between the larger stones to stabilize them. Extra stones are backfilled behind them for drainage to help prevent erosion and smaller stones are also filled into the spaces in the front to stabilize the larger stones. Note that there is no mortar used. This allows the stone walls to have some flexibility which is what has helped them to survive for hundreds of years in earthquake prone Japan.
The style of wall indicates the pattern of how the stones are arranged. These two patterns below are used with all of the different types explained in the next section.
The stones used are of various sizes so that there is no particular pattern to the face of the stone wall.
Most of the stones are roughly the same size so that they line up across the face of the wall.
Stone walls can be categorized by how much the stones are processed to fit together in the wall. Walls that use unprocessed stones tend to be older, while walls that make use of more highly shaped stones are newer making use of newer techniques and tools.
These walls use unshaped stones. They are either stones that were used in their natural shape or were split without any further shaping. This type of wall is comparatively weak and high walls cannot be built. It also provides many footholds and handholds making it relatively easy for attackers to climb.
The stones are pounded tightly into place and the corners and rough edges are smoothed some to help them fit together better. The face of the stone is also chipped away to make it more flat. The remaining holes are filled with smaller stones to tightly fill the gaps. This makes a stronger wall than Nozurazumi and these walls can be built higher.
In this type of wall, all the stones are heavily processed and shaped to fit exactly with the surrounding stones. There are almost no holes or empty spaces and no smaller uncut stones filling the spaces between stones. Since water cannot seep out through the spaces they often needed to build in some holes for drainage.
This is basically a special type of Kirikomihagi where all the stones are cut with five or six sides and fitted together.
Tanizumi / Otoshizumi
The stones are fit together at an angle so they have a diagonal pattern instead of horizontal. It takes advantage of the weight of the stones to hold them in place. This construction was actually comparatively easy and often used in the later Edo Period.
This method uses river stones that were naturally shaped by the river to be round. The only castle I know of that makes use of this is Yokosuka Castle in Shizuoka Pref.
Trenches, ditches, empty moats, or dry moats are one type of earthworks that cover a wide range of trench like fortifications around castles. In flatland castles they are often similar in structure to water moats but without the water. Both water moats or dry trenches have their own unique advantages and disadvantages. For example, it can be harder for intruders to hide in a dry moat and there no natural water sounds that might disguise entry. The slick clay sides of many castles in the Kanto region were especially slippery and difficult to climb. I have had a difficult time even in hiking boots getting up only slight slope where there is no grass for traction. On the other hand, water moats, where feasible, can be a good psychological deterrent. Attackers don't know how deep they are or what is underneath. A wet intruder will likely leave a trail and they will need to expend more energy to get across.
When you see photos or visit these locations yourself you may think that these trenches are shallow and would not be much of a deterrent but keep in mind that they have filled with leaves and dirt and have been eroded significantly over the last 400 years. What is now a meter or less deep may have been two or three times that deep at one time.
Some terms related to trenches that you may see include:
This is a deep trench cut across a mountain ridge to impede attackers from easily climbing the ridge. You see a lot of these on the path to mountaintop castles and it's usually the first sign that you've entered a castle. Unless there are signs to point them out or you are familiar with seeing horikiri you might not notice them at all. But, if you think about it, such a sudden steep dip in a ridge is very unnatural.
A horizontal trench across a slope or mountain. It can also provide an easier route for defenders to cross a slope.
A vertical trench running down a slope. It can be used to impede attackers from easily crossing a slope and can force them into a kill zone.
Several parallel tatebori across one slope on a mountaintop castle. They may be difficult to see if the are on a steep side of the castle that you cannot get to.
A wider trench with square depressions carved out. It forces attackers to either walk the narrow ridges and be easily fired upon or scale up and down the slick clay walls putting them in vulnerable positions and using a lot of physical energy. These are often attributed to the Hojo but the Hideyoshi's Osaka Castle had great shojibori too. Unfortunately you can not longer see them. The only really good shojibori you can see today are at Yamanaka Castle in Shizuoka but many more have been excavated and reburied over the years.
A trench with ridges across them. This is similar in design to the shojibori but instead of a "waffle" like design it is only a single row of dugout depressions.
Empty Moats (空堀)
These are the moats you are more likely to see at flatland castles. They are similar in size and shape to water moats but without the water.
The Japanese term yagura literally means a storehouse (kura) for arrows (ya), but yagura were used to store all manner of weapons, food and supplies. Yagura were not just storehouses, but vital defensive platforms and lookout towers that were placed at strategic locations throughout the castle. Most corners of a bailey had a yagura, often called a sumi yagura (corner yagura). These corners provided a wide field of view and two sides for flanking fire. The corner yagura also protected the vulnerable corners of stone walls which were much easier to climb than the straight sheer sides.
You can sometimes guess what was stored in a yagura or its purpose from the name: Teppo Yagura (guns), Hata Yagura (flags), Yari Yagura (spears), Shio Yagura (salt), among many others. There were also other special function yagura such as Taiko Yagura which kept a drum to sound out the time, Tsukimi Yagura for viewing the moon, and Ido Yagura for housing a well. Sumi Yagura (corner yagura) often had special naming conventions too. They were named according to the 12 signs of the zodiac as placed on the face of a clock. So with north at 12 o'clock a northwest yagura was called Ushitora Yagura, a southeast yagura was Tatsumi Yagura, southwest was Hitsujisaru Yagura and Northwest was Inui Yagura.
Yagura were mostly built in the sotogata style, with the same characteristics of many main keep. Sotogata have a square base with each level a size smaller than the lower one. There are few extant yagura in the borogata style, but some examples are the Utoyagura at Kumamoto Castle and Nohara Yagura at Iyo Matsuyama Castle and the Fushimi Yagura at Fukuyama Castle. See the Main keep page for more details about these structure types.
Seiroyagura is one of the earlier forms of yagura. It is a simple structure made from wooden beams in a square. They were used as watchtowers in earlier castles and were erected on the battlefield to provide commanders with a better view.
3 level yagura (三重櫓)
main keeps are basically really big yagura that evolved to 3 or more levels. Especially, in eastern Japan many castles built a large 3 level yagura in place of a main keep. Such main keep were also called gosankai yagura. The main keep of Hirosaki Castle and Marugame Castle are actually 3 level yagura. At Edo Castle, the 3 level Fujimi Yagura was used in place of the main keep after it burned down too.
Gosankai Yagura (御三階櫓)
2 Level Yagura (二重櫓)
2 level yagura is the most typical yagura type and there are many surviving examples throughout the country. You see lots of unique shapes and uses for these yagura.
1 level yagura
This is the simplest yagura type. It's too short to be used as a lookout tower and not usually used as a sumiyagura. Hirayagura is most frequently used on the edge of an outer bailey like a sannomaru bailey that has no dirt walls. It is also frequently used as a connecting yagura to join gates, larger yagura or main keep.
Tamonyagura is a hirayagura that has been stretched out. It can be used in place of dirt walls atop moats and embankments. Tamonyagura are often found connected to corner sumiyagura or main keep. They can be used to store goods, but also function as a very strong defensive platform.
Dobei are the white walls you commonly see at castles. They are the simplest and most inexpensive defenses available. Dobei originally lined the top of most moats, stone walls and encircled most of the baileys linking together gates and yagura. Many castles had at least one kilometer of walls and Edo Castle had more than 10km. Despite the fact that there were so many such walls during the Edo Period, if you added up all the extant walls today you would only find a little over a kilometer. The majority of extant walls are at Himeji Castle and the longest single extant section is the Nagabei at Kumamoto Castle. These walls evolved from simple structures of wooden planks nailed to a fence. The walls were strengthened and thickened to prevent arrows from piercing them, to prevent fire and later to prevent bullets from easily passing through.
Dobei walls are built by erecting pillars approximately 1.5 meters apart. In between the pillars is a lattice of bamboo or wood strips. Mud and clay were then layered over this lattice up to about 20cm thick. The clay was often mixed with some strong Japanese grass (wara) for added strength and to prevent cracks. Earlier forms of these walls were not covered in plaster which gave them a sandy yellow color. In the picture above from Sakasai Castle you can see a wall with no plaster that shows this yellow color and you can also make out some grasses embedded in the clay. Edo Period dobei were usually covered in hard white plaster which increased their strength and helped prevent weathering. Atop the wall they had tile roofs and often had loopholes for firing arrows or guns. Walls also frequently had support posts behind them to increase their strength especially for walls along the top of stone walls or other places where the foundation was not as solid. Some walls also contained strategically placed rock chutes to drop rocks on attackers. Click the pictures below to enlarge these displays of wall construction.
There are some extant variations of these walls that can be divided into neribei and tuijibei. Neither of these have the kind of wooden pillars or interior framework of the usual walls. Neribei are constructed from dried clay bricks or old tiles that are mortared together with clay and covered with a layer of hard plaster. Neribei were employed at Himeji and Bitchu Matsuyama castles to quickly build some walls.
Tuijibei are made from pounding a mixture sand and clay in 3-5 cm layers. They are about 1 meter thick and up to 3 meters tall. They have a distinctive wooden framework on the outside and are topped with a tile roof. These are very strong walls, but their thickness makes it impossible to build in loopholes and they are very time and labor intensive to build. For these reasons they were not commonly used at castles. There is a small section by the Mizu no Ichi gate at Himeji Castle and the Ninomaru of Nijo Castle is surrounded by impressive Tsuijibei.
Loopholes / Sama (狭間)
Loopholes were holes built into the walls for firing arrows or guns. Loopholes designed for arrows were generally tall rectangles and those for firearms were circles, triangles, or squares. Some loopholes were hidden by a door or plug that matched the surface on the outside to prevent detection by attackers. These are called kakushizama as you see in the last two photos below.
Earlier castles were mostly mountaintop castles so they rarely had water filled moats. With the evolution of hilltop and flatland castles, water filled moats became more common. Water moats often connected with nearby wetlands, lakes, or the ocean to fill with water. During peaceful times, these waterways could also be used for commerce and transportation.