186.Kaneda Castle Patr1

Kaneda Castle was one of the ancient mountain castles in western Japan. They were built by the Imperial Court after the Battle of Baekgang, Korea in 663. Kaneda Castle was at the foremost line against possible invasions from the alliance of Tang and Silla. This was because it was located in Tsushima Island, only about 50km away from Korea.

Location and History

One of Ancient Maintain Castles

Kaneda Castle was one of the ancient mountain castles in western Japan. They were built by the Imperial Court after the Battle of Baekgang, Korea in 663. Japan tried to help Baekje, but was beaten by the Tang and Silla alliance. Emperor Tenchi was scared of invasions from the alliance, so he ordered these castles’ constructions. Kaneda Castle was at the foremost line against the alliance because it was located in Tsushima Island, only about 50km away from Korea.

The locations of the major ancient mountain castles

The map about the Battle of Baekgang (licensed by Samhanin via Wikimedia Commons)

These castles are also called Korean style mountain castles which were established in Korea and brought to Japan with the instructions from the refugees from Baekje. There had been many battles in ancient Korea (part of present day North and South Korea) due to invasions from China and the internal conflict with three countries, Baekje, Silla and Goguryeo. The style involves surrounding the whole mountain by stone walls or earthen walls, which was very different from that of Japanese castles that would be later established. If people in Korea at that time were attacked by enemies, they would escape to their mountain castle, wait for the enemies’ supply to run out and counterattack the enemies. This style was applied to Japan to immediately prepare for possible invasions from the alliance.

The diorama of Kaneda Castle Ruins, exhibited by the sightseeing information center Fureaidokoro Tsushima

Stone Walls mostly surround Mountain

The Imperial Court built Mizuki in 664 as the 1st ancient mountain castle. After that, it also built Ono and Kii Castles in 665, and then, Takayasu, Yashima and Kaneda Castles in 667, according to Nihon-shoki, the oldest official chronicles of Japan. It is thought that nearly 30 ancient mountain castles, including recorded and non-recorded ones, were built along the estimated routes of the invasions around the northern Kyushu Region and Seto Inland Sea. The Imperial Court also drafted soldiers from eastern Japan, who would be called Sakimori, and sent them to the northern Kyushu Region to protect and monitor this area. The fire-signal system was also developed in the region to rapidly inform the signs of what happened.

The ruins of Mizuki
The ruins of Ono Castle
The ruins of Kii Castle

Kaneda Castle was built on Joyama Mountain facing Aso Bay in the central part of Tsushima Island. The castle was about 15km away to the north from the provincial capital of Tsushima, near the current Izuhara Port. This was probably because the usage of the castle would follow that of the mountain castles in Korea like a shelter. Its perimeter was about 2.2km, which was mostly covered with stone walls, in contrast to other ancient mountain castles like Ki-no-jo, mostly surrounded by earthen walls. The northern and western sides of the castle were along the steep ridges of the mountain, which were naturally very defensive. On the other hand, the southern side faced the valley which would be the entrance to the castle and the eastern side was beside the bay. That’s why several gates were built and the stone walls were higher on these sides. It is thought that there were no office buildings and no warehouses, but only buildings like barracks the Sakimori soldiers used inside the castle, according to the results of excavations.

The aerial photo around the castle

The Aso Bay
The stone walls of Kaneda Castle (the southeast stone fortress)
The earthen walls of Ki-no-jo

The relief map around the castle

Castle is shortly abandoned because of Stable Diplomatic Relations

Meanwhile, the diplomatic negotiations with foreign countries continued. For, example, Tang and Goguryeo started to fight with each other in 666. Both countries asked Japan for help. While Emperor Tenchi moved the capital from Asuka in Nara to Otsu, more interior than Asuka in 667 and made the first national census in 670 probably to prepare for the next war. The tension between Japan and Tang reached its peak after Tang defeated Goguryeo in 668. It is said that Tang actually planned to invade Japan then. However, the plan was canceled as Tang and Silla battled each other in 670. The battle resulted in Silla repelling Tang and the unification of Korea Peninsula in 676. The next emperor, Tenmu, also made friendly relations with Silla, which meant the serious threat to Japan had gone.

The ruins of the imperial palace of Otsu (licensed by Saigen Jiro via Wikimedia Commons)

As a result, there would be no need for maintaining all the ancient mountain castles. Many of them including Kaneda Castle were repaired or improved by the end of the 7th Century. However, it is thought that Kaneda Castle was abandoned at the beginning of the 8th Century. Manyoshu, the oldest anthology of Japan, which was first published in the late 8th Century, contains a Tanka poem created by a Sakimori soldier who was in charge of Tsushima Island. Interestingly, this Tanka was published nearly a century after the castle was active. The life of this great castle was only 30 to 40 years.

The ruins of Kaneda Castle (the first gate)

To be continued in “Kaneda Castle Part2”


This is never a devil’s castle.

立地と歴史~Location and History

伝説の城~Legendary Castle

This castle named “Kino-jo”, or Devil’s Castle, located in what is now Okayama Prefecture, is mysterious. No one knows the origin of the castle, because it is not recorded in any document at all. In folk stories, a devil called “Ura” from Korea lived in the castle. He did bad things around the area. The Imperial Court sent a noble called “Kibitsu-hiko”. Kibutsu-hiko fought with Ura and defeated him. People call the castle Kino-jo based on this belief. It is also said that the belief might be connected to one of the most popular folk tales in Japan called “Momotaro”.

城跡にある温羅の記念碑~The monument of Ura at the ruins
吉備津彦を祀る吉備津神社~Kibitsu Shrine worshiping Kibitsu-hiko

実は古代山城~In fact, Ancient Mountain Castle

However, it has recently been found out that the castle was one of ancient mountain castles in western Japan by researches and studies. They were built by the Imperial Court after the Battle of Baekgang, Korea in 663. Japan tried to help Baekje, but was beaten by the ally of Tang and Silla. Emperor Tenchi was scared of an invasion by the ally, so he built these castles for protection. The ruins of Kino-jo are very similar to other recorded ones. Historians have concluded Kino-Jo must be a an ancient mountain castle.

白村江の戦いの図~The map about the Battle of Baekgang(licensed by Samhanin via Wikimedia Commons)

The castle was on the southern edge of Kibi-kogen Highlands which is about 400m above sea level. The cliffs are steep, but the top of the highlands are relatively smooth. It is also about 10 km away from the ancient coastline. It had the best location to be a strong point. Unlike most Japanese castles, ancient mountain castles mainly consisted of an outer fortification. Their center area had facilities like warehouses and barracks.

城周辺の起伏地図~The relief map around the castle

土塁に囲まれた城~Castle surrounded by Earthen Walls

In the case of Kino-Jo, the perimeter was about 2.8 km, about 90% of it was earthen walls, and the rest was work of stone. The castle also had four gates, six water gates, and a turret called “Kakuro”. In particular, the earthen walls were built in a method called Rammed Earth or “Hanchiku”. The method consists of building many earthen layers by ramming down each layer of soil. In addition, stones were placed in front and back of the walls. Wooden fences ran parallel to wall, inside the fortification around the gates.

鬼ノ城の全体模型~The full model of Kino-Jo(鬼城山ビジターセンター)
復元された門、土塁、敷石、木柵~The restored gate, earthen walls, placed stones, and wooden fences


Now, the ruins of Kino-jo have been developed with the Kinojosan Visitor Center as the starting point. The visitor center has exhibitions about the ruins. You can climb up from the center to the outline of the ruins which can also be used for trekking. If you go along the outline counterclockwise, the first part is the restored area.

城周辺の航空写真~The aerial photo of around the castle

復元エリア~Restored Area

The restored West Gate is outstanding. Its earthen walls, stone walls, stone pavement, and wooden fences were rebuilt in the original way as much as possible. The gate building was also rebuilt referring to similar examples at that time. The Kakuro turret in front of the gate is partly restored. Its foundation was rebuilt in the same way as the West Gate, but its structure couldn’t be rebuilt because there are no modern examples of it.

復元された西門~The restored West Gate
土台だけ復元された角楼~Kakuro Turret, only its foundation was restored.

トレッキングコース~Tail for Trekking

The other ruins were repaired and shown as they are, but are great to visit. For instance, the Second Water Gate has a drain which still works. You should check out wild natural stones around the East Gate Ruins.

第二水門~The Second Water Gate
東門跡~The East Gate Ruins
自然石群~The natural stones

Passing the gate ruins, the high stone walls look great and the views of Okayama Plain are very beautiful. That also meant defenders in the castle were able to watch the situation outside. There are some other ruins scattered about where the warehouses once stood.

高石垣~The high stone walls
岡山平野の眺め~A view of Okayama Plain
倉庫群跡~The ware houses ruins

その後~Later History

Kino-Jo was most likely abandoned in the first 8th century. After that, the ruins were used for temple grounds or training grounds for Buddhists. In the “Sengoku” or Warring States Period, warriors used part of them again as a castle. People thought the castle was originally built by a devil for some time.

仏教徒が修業を行った痕跡~A trace of Buddhist training

In 1970, a historian first explore the ruins as a historic site, and suggested that it might be an ancient mountain castle. That was proved by academic research in 1978. As a result, the ruins were designated as a National Historic Site in 1986. Since then, Soja City has been rebuilding them.

復元された西門と土塁の全景~The whole view of the West Gate and the earthen walls

私の感想~My Impression

I think that the ruins of Kino-Jo are one of the most well conserved ones in Japan. Because part of the ruins were restored to look like the originals, and the others were preserved in good conditions. it’s a good balance. You can also choose to learn history while working up a sweat.

版築で復元された土塁~The restored earthen walls by Rammed Earth

ここに行くには~How to get There

I recommend using a car to get there. It takes about 8km away from the Okayama-Soja IC on Sanyo Expressway. The visitor center offers a parking lot.

リンク、参考情報~Links and References

鬼ノ城、総社市公式観光WEBサイト(Soja City Official Site)
・「鬼ノ城/谷山雅彦著」同成社(Japanese Book)
・「歴史群像45号/鬼ノ城、吉備路を睥睨する古代山城」学研(Japanese Book)