After Kokokuji Castle was abandoned, the area was turned into farm. In 1857, people founded the Homi Shrine at the ruins for prosperity after a large earthquake and famine. Numazu City has been investigating and excavating the ruins since 1982. The ruins were designated as a National Historic Site in 1995. The city is thinking about developing the ruins as a historical park with restored water moats.
Homi ShrineThe dry moatThe development plan of Numazu City on the signboard at the site
My Impression
I thought that Kokokuji Castle was just the castle for Soun Hojo to make his first career. However, the castle had the history of over 100 years after him. That was because the castle was at a very important area and had a good location. I think that the ruins of Kokokuji Castle are a good place to visit in Numazu City. If the weather is fine, you can also see the top of Mt. Fuji from the ruins.
The remaining stone wallsThe Main Enclosure surrounded by the earthen wallsYou can also see the top of Mt. Fuji
How to get There
If you want to visit there by car: It is about 20 minutes away from Numazu IC on Tomei Expressway. There is a parking lot in the ruins. By public transportation, it takes about 30 minutes on foot from Hara Station. Or take the Fujikyu City Bus bound for Higashi-Hiranuma or Fuji-eki from Numazu Station, and get off at the Higashi-Nekoya Bus Stop. To get Hara Station or Numazu Station from Tokyo: Take the Tokaido Shinkansen Super Express, and transfer to the Tokaido Line at Mishima Station.
The earthen walls and the dry moats are outstanding.
Features
Going to Main Enclosure from Third Enclosure
Now, the marshland around Kokokuji Castle has been turned into the city area. Only the ruins of the castle remain. The modern Nekata Road goes through the ruins. If you visit the ruins by car, you can park at a parking lot in the Third Enclosure, the lowest one out of the three main enclosures. You can walk up from the parking lot to the top Main Enclosure along a gentle slope. The middle tier is the Second Enclosure which looks flat and empty, but it had a round-shaped moat in the past.
The aerial photo around the castle
The entrance of the castle ruinsThe Third Enclosure with a parking lotThe Second Enclosure which had a moat
Main Enclosure and its Earthen Walls
The Main Enclosure is still surrounded by large high horseshoe-shaped earthen walls. It’s a fine sight. Inside of the enclosure, there are the monuments of Soun Hojo and Yasukage Amano, and the Homi Shrine which was founded in the Edo Period. The earthen walls on the back of the enclosure are 6m high, and you can walk up to the top by the steps. You can also see the stone walls partly built under the top. There are also foundation stones on the top which are considered the ruins of the base for the Main Tower, but it is thought that a kind of turret was there. You can see a view of the town area with Izu Pninsula on the south from the top.
The earthen walls surrounded by the horseshoe-shaped earthen wallsThe monuments of Soun Hojo and Yasukage AmanoThe Homi ShrineThe stone walls under the topThe stone foundation for “the base for the Main Tower” on the topA view from the top
The Dry Moat of Main Enclosure and Northern Part
The large deep dry moat also remains behind the Main Enclosure. You can walk down from the top to the bottom of the moat by the steps as well. It is 18m deep where you can look up the top. You may wonder about the several earthen holes in the walls which were built as air-raid shelters during World War II. The edge of the moat leads to the side of the ruin of the castle which was part of the marshland in the past.
The dry moat behind the Main EnclosureThe air-raid shelters built during World War IIThe western side of the ruins
There is also the North Enclosure over the dry moat on the north. Another round-shaped moat was over there, and it was turned into the railway track of Tokaido Shinkansen Super Express. Historians speculate that the set of the round-shaped moats were built by the Takeda Clan or the Tokugawa Clan who used to build similar systems in other castles.
The Main Enclosure seen from the North EnclosureThe railway track of Tokaido Shinkansen Super Express which was a moat
Kokokuji Castle was located in what is now Numazu City, Shizuoka Prefecture. The area of the city was in Suruga Province (now central part of Shizuoka Pref.) which many warlords tried to take over in the 16 Century during the Sengoku Period.
The location of the castle and the range of Suruga Province
The castle was on the southern edge of the hilly terrain of Ashitaka-yama Mountain. There was a marshland to the south, east and west of the castle which was as natural hazard that helped to protect the castle. The castle was built using the natural terrain of the mountain and marshland. The castle was also an important point for transportation. A road at the foot of the mountain called the Nekata Road passed beside the castle. In addition, the Takeda Road close to the castle ran from the Nekata Road to the Tokaido Road at the seaside.
A relief map around the castle
The two roads are still connected to the castle ruins
The castle mainly consisted of three enclosures on the hill in a terraced manner. The Main Enclosure was at the highest, and there was a large deep dry moat behind the enclosure to prevent enemies’ attacks from the north. The castle even had ports on both sides for ships on the marsh.
Part of the illustration of Shinkokuji Castle in Suruga Province, exhibited by the National Diet Library (It is supposed to be Kokokuji Castle)
The castle itself might have been simple but is well known for its history. This is because some history books say that Kokokuji Castle was the first castle for a famous warlord, Soun Hojo to govern. He was one of the earliest warlords in the late 15 Century who supported the Imagawa Clan in Suruga Province. He was given the castle by the clan in 1487. His success story starts at this castle, and he went on to capture a part of the Kanto Region. His descendants followed in his footsteps to capture the other parts of the Kanto Region.
The replica of the portrait of Soun Hojo, owned by Odawara Castle (licensed under Public Domain via Wikimedia Commons)
However, there is no other evidence of the castle existing at the same time as Soun. The first appearance of the castle in a public document can only be traced back to 1549. At that time, Yoshimoto Imagawa ordered that the Kokoku-ji Temple be moved to another location to make space for building a new castle there. What is the truth about the matter? A historian gives us an interesting hypothesis that the castle was a temple called Kokoku-ji when Soun owned it. Kokoku-ji is originally a name of temple (“ji” means temple in Japanese). Kokokuji Castle is thought to be named after the Kokoku-ji Temple.
The statue of Yoshimoto Imagawa at Okehazama Battlefield Park (taken by HiC from photoAC)
The historian suggests another speculation about why the castle was built. A period of peace once came to the area around Suruga Province with Imgawa, Hojo, and Takeda Clans when the castle was built. Castles were basically built for battles, but Kokokuji Castle might have been built for the meeting with the three clans or as a symbol of peace. It is said that the three clans had a conference for their alliance at the Zentokuji-Temple. The temple may have been Kokokuji Caste.
The portrait of Shingen Takeda, the lord of the Takeda Clan at that time, owned by Jimyo-in Temple (licensed under Public Domain via Wikimedia Commons)
Unfortunately, the alliance broke in 1568, while Kokokuji Castle was involved in war. The lords of the castle were rapidly changed several times from the Imagawa Clan to the Hojo, Takeda, Toyotomi, and Tokugawa Clans. As the number of the lords increased, the range of the castle seemed to become larger. In 1601, Yasukage Amano under Tokugawa became the last lord of the castle and the founder of the Kokokuji Domain. He governed the area well, but he ran away from the castle because of trouble between his citizens and others. The castle was finally abandoned when the domain was abolished in 1607.
Yasukage Amano from the Battle of Komaki-Nagakute folding screens (licensed under Public Domain via Wikimedia Commons)
