The Main Tower remained, but was burned down, then restored.
Later History
After the Meiji Restoration, Ogaki Castle was abandoned and almost all the buildings of the castle were demolished. A lot of moats were also reclaimed except the Outer Moat called Suimon-gawa River. They were turned into the city area.
Only the Main Tower and two turrets at the Main Enclosure remained. Especially, the external design of the Main Tower was used when the Main Tower of Gujo-Hachiman Castle was rebuilt in 1933.
However, those of Ogaki Castle were unfortunately burned down by the Ogaki Air Raid in 1945. After World War II, they were externally restored in 1967 using the design of the original ones and Gujo-Hachiman Castle instead.
Features
Around Main Tower as Ogaki Park
The map around the castle
Today, only around the Main and Second Enclosures remained as the Ogaki Park. Part around the Second Enclosure is a normal park and the Main Enclosure has a historical atmosphere. No moats unfortunately remained around the enclosure while the roads around it are probably the former moats.
It has two gates, the Western Gate was built in the present time, and the Eastern Gate is the original, but was moved from another place which was once called Yanagikuchi-mon Gate. There are also the externally restored Inui and Ushitorra Turrets alongside the gates.
The restored four-level Main Tower is inside the enclosure, which is actually a modern building and used as a historical museum.
A castle which might have been a crucial battle field
Location and History
Battlefield of Crucial Event
The Battle of Sekigahara have been one of the most crucial events in the Japanese History. The East squad led by Ieyasu Tokugawa and the West squad led by Mitsunari Ishida battled each other at Sekigahara Field in 1600 before the Tokugawa Shogunate was established. Most Japanese people know about Skigahara, but what about Ogaki Castle? In fact, the castle might have become the battle field of the crucial event if the situation changed (if Mitsunari decided to stay in that castle).
Ogaki Castle as Important Point
Ogaki Castle was located in the western part of Mino Province (now Gifu Prefecture) connecting to western Japan trough Sekigahara. It is uncertain when the castle was first built, but it became important as the country had been unified in the late 16th Century during the Sengoku Period. The ruler, Hideyoshi Toyotomi said “Ogaki Castle is an important point” and actually sent his relatives to the castle as its lords. The castle was built on a plain land, but surrounded by several moats and rivers, which looked like a Water Castle.
The location of the castle
After Hideyoshi died in 1598, a political conflict began between Ieyasu Tokugawa and Mitsunari Ishida. Mitsunari doubted Ieyasu would take over the power of Hideyoshi’s young son, Hideyori who was still the ruler of Japan. Ieyasu went to eastern Japan to conquer the Uesugi Clan who were against Ieyasu in June 1600. Mitsunari raised an army to defeat Ieyasu in July in western Japan. The East and West squads were expected to fight in central Japan including Ogaki Castle and Sekigahara. Mitsunari stayed in Ogaki Castle as his stronghold and built several battle castles, such as Nangusan Castle, on the mountains behind Ogaki Castle for his allies to stay. He was waiting for Ieyasu’s attack at the castle doing as best as he could. He also built large mountain castles such as Matsuoyama Castle around Sekigahara Field to call for a great warlord, Terumoto Mori and his master, Hideyori to support him. If his plans came true, Ieyasu might have been defeated because Hideyori was still Ieyasu’s master as well.
Why did Mitsunari leave Castle?
However, on September 15th, Mitsunari suddenly got away from the castle, fought against Ieyasu at Sekigahara Field, and defeated in a day. Why did Mitsunari cancel his own plan and choose the field battle he probably dislike but Ieyasu was more familiar with? The long-accepted theory says Mitsunari noticed Ieyasu tried to skip Ogaki Castle and attack western Japan directly. Mitsunari and his allies were one jump ahead of Ieyasu, and took up their positions at the field. They fought well in the first part, but finally got defeated by the betrayal of Hideaki Kobayakawa, one of their allies, during the battle. This story is dramatic, so Japanese people believed it for a long time. However, it was first seen in war chronicles in the Edo Period, about 60 years later than the actual battle. I also think the reason above is too weak for Mitsunari to leave the castle.
Some new studies may tell us the real reasons why Mitsuhide left Ogaki Castle. According to these studies, Hideaki Kobayakawa was expected to support the East quad earlier than what the previous theory says. Hideaki occupied Matsuoyama Castle and moved to Sekigahara Field before the battle against Mitsunari’s plan. If he stayed, he could have been attacked on both sides. Mitsunari might have noticed Hideaki’s movement, so this may be why he quickly moved to Sekigahara to avoid the worst situation. One theory says Mitsunari tried to get to another mountain castle, called Tama Castle, to fight against Ieyasu and Hideaki, but was unfortunately defeated around Sekigahara Field. After the battle, some Mitunari’s retainers still stayed in Ogaki Castle, however, they were outnumbered. They surrendered after being besieged by the East squad for about a week.
Ogaki as City of Water
After the Battle of Sekigahara, Ogaki Castle was still recognized as an important point connecting eastern and western Japan. Several different lords governed and improved the castle. For example, the Ishikawa Clan completed the Outer Moat and the Matsudaira Clan renovated the four-level Main Tower. The tower was in the Main Enclosure which is connected with the Second Enclosure where the Main Hall for the lord was. Both enclosures were surrounded by the Inner Moat. Overall, the tripled moats surrounded the castle. In addition, the castle town was consolidated with the castle by waterways and rivers. That’s why Ogaki City has been called The city of water. Since 1635, the Toda Clan governed the castle and the area was called the Ogaki Domain until the end of the Edo Period.
From the Eastern Enclosure, you can enter the Main Enclosure by passing through two gate ruins and the Nagatsubone Enclosure between them.
The inside of the Main Enclosure is a square now. You can see from there views of the city area far away and the castle area around such as the Demaru Enclosure which also protected the Main Enclosure, but it is now used as a parking lot.
You can also see the Uzumi-mon Gate Ruins which is the entrance from the Second Enclosure. It is interesting to see the stones on the steps are all cut in the shape of a triangle.
Later History
After the Meiji Restoration, Iwamura Castle was abandoned and all the buildings of the castle excluding the Main Hall at the foot were demolished. The hall was also burned by a fire in 1881. Iwamura History Museum opened in 1972 at the site of the former hall and part of the hall was also restored in 1990. On the mountain side, Ena City, which owns the ruins, recently excavated and researched them to develop and preserve them. The city aims to someday make the ruins designated as a National Historic Site.
My Impression
When I visited the ruins of Iwamura Castle, I made a mistake choosing my parking spot. I wanted to walk around the ruins from the foot to the top. However, my car navigation system led me to the parking lot near the top automatically. Therefore, I had to climb down to the foot first, then I returned back to the top. For visitors who want to see the entire ruins should park at the foot. If you want to see only the great stone walls on the top, you can park at the Demaru Enclosure, which is few minutes on foot from the Main Enclosure on the top.
How to get There
I recommend using a car when you visit the castle ruins. It is about a 20-minute drive away from Ena IC on the Chuo Expressway. There are two parking lots near the top and at the foot of the ruins If you want to use public transportation, It takes about 30 minutes on foot from Iwamura Station on the Akechi Railway to arrive at the foot. To get to Iwamura Station from Tokyo or Osaka: Take the Tokaido Shinkansen super express, transfer to the Chuo Line at Nagoya Station and transfer to the Akechi Railway at Ena Station.