176.Ichinomiya Castle Part2

Unexpected stone walls on the mountain

Features

Well-developed Trail to Castle Ruins

If you drive to the ruins of Ichinomiya Castle, you will go through the route on the narrow area sandwiched by Akui-gawa River and mountains. You can see that it is a good location for defending the castle. The entrance of the trail to the ruins is opposite of the Ichinomiya Shrine. You will need to climb to the top of the 144m high mountain, but the trail is well developed with stone steps.

The location map at the site, adding English names

The map around the castle

The entrance of the trail
The well-developed trail with stone steps

After climbing for a while, you will see a Vertical Moat or Tate-bori on the slope along the trail to prevent enemies from attacking. If you go to the branch nearby, you can see the ruins of the Warehouses.

The Vertical Moat
The ruins of the Warehouses (licensed by ブレイズマン via Wikimedia Commons)

Defense System using Natural Terrain

Going back to the main trail, you will reach an artificial steep cliff called Kiri-gishi under several enclosures. You can also see a fountain at the foot of the cliff. You will need to climb a zigzagged trail on the cliff to go further.

The artificial steep cliff
The fountain under the cliff
Climbing on the cliff

Even after climbing, you will still be under the bottom of an artificial valley called Hori-kiri. Enemies could have been counterattacked from the enclosures above. The valley divides the main portion of the castle and the Saizo-maru Enclosure. If you turn left at the valley, you will reach the Saizo-maru Enclosure. This enclosure is also called the Third Enclosure. “Saizo” originates from the name of the retainer who was responsible for the enclosure.

Being under the bottom of the valley even after climbing
The entrance of Saizo-maru Enclosure
The inside of Saizo-maru Enclosure

Going to Center of Castle

If you turn right at the valley, you will reach the ruins of the gate for the main portion which have two main enclosures – the Myojin-maru Enclosure and the Main Enclosure. These enclosures are connected by a long and narrow enclosure called the Belt Enclosure or Koshi-guruwa

The ruins of the gate for the main portion
The Belt Enclosure

If you turn right again at the gate ruins, you will be in the Myojin-maru Enclosure. This enclosure is also called the Second Enclosure and the spot where the ruins of the building with veranda, maybe for sightseeing, was found. You can even now see a good view of the center of Tokushima Prefecture to the east.

The entrance of Myojin-maru Enclosure
The inside of Myojin-maru Enclosure
A view from Myojin-maru Enclosure

Great Stone Walls of Main Enclosure

If you go back to the gate ruins and go left from the front of it, you will finally reach the Main Enclosure on the top of the mountain. You may be surprised to suddenly see the great stone walls which were built by the Hachisuka Clan. The stone walls of this castle are very rare and beautiful because they were piled up using stones with a dark-green striped pattern called chlorite-schist. These stones are also known as Green Stones of Awa. The same pattern of stone walls can also be seen at Tokushima Castle that the Hachisuka Clan built after they used Ichinomiya Castle.

The stone walls of the Main Enclosure
They were built using chlorite-schist
The stone walls of Tokushima Castle

There is only the small building of Wakamiya Shrine. The stone foundations of the Main Hall for the lord were found recently, which were also built by the Hachisuka Clan. You can also see a good view of the area around, including Akui-gawa River.

The inside of the Main Enclosure
The small building of Wakamiya Shrine
A view from the Main Enclosure

To be continued in “Ichinomiya Castle Part3”
Back to “Ichinomiya Castle Part1”

176.一宮城 その2

山上に突然現れる石垣

特徴、見どころ

よく整備された登山道

もし一宮城跡に車で行かれるのでしたら、鮎喰川と山地に挟まれた狭い地域を通る道路を行くことになります。城を守るためにはよい立地であることがわかると思います。城跡への登山道入口は、一宮神社の反対側にあります。ここから標高144mの山頂まで登っていく必要があります。しかし、登山道には石段があり、よく整備されています。

現地の案内図より

城周辺の地図

登山道入口
石段が作られ、よく整備されています

しばらく登っていくと、登山道に沿った坂に竪堀を見ることができます。これは、敵の攻撃を防ぐための仕掛けです。近くにある分かれ道に入っていくと、倉庫跡があります。

竪堀
倉庫跡 (licensed by ブレイズマン via Wikimedia Commons)

自然の地形を生かした防御システム

登山道の本道の方に戻って進んでいくと、いくつかの曲輪の下にある、切岸と呼ばれる人工的に作られた急崖に至ります。この崖下には、湧水も見られます。ここから更に曲がりくねった登山道が崖を伝って登っていきます。

切岸によって作られた急崖
崖下の湧水
崖を登っていきます

崖を登った後でも、堀切と呼ばれる人工的に作られた谷の底にたどり着くのみです。敵の軍勢は、上方の曲輪から反撃を受けることになったでしょう。この谷によって、城の中心部と、才蔵丸という曲輪が分けられています。ここから左の方に行けば、才蔵丸に着きます。この曲輪は、三の丸とも呼ばれています。「才蔵」とは、かつてこの曲輪を任せられていた部将の名前に由来しています。

崖を登ってもまだ堀切の底です
明神丸入口
明神丸内部

城の中心部へ

谷から右の方に行ってみると、二つの主要な曲輪(明神丸と本丸)がある城の中心部への門跡に至ります。この二つの曲輪は、腰曲輪と呼ばれる細長い曲輪によってつながっています。

城の中心部への門跡
腰曲輪

その門跡から再び右の方に曲がっていくと、明神丸です。この曲輪はまた二の丸とも呼ばれていて、眺望を楽しむためと思われる縁側付きの建物跡が見つかった所です。今でもここからは、東の方角に徳島県中心部の景色がよく見えます。

明神丸入口
明神丸内部
明神丸からの景色

本丸のすばらしい石垣

先ほどの門跡に戻り、その前から見て左の方にいくと、ついに山の頂上にある本丸に到着します。蜂須賀氏が築いたすばらしい石垣が突然現れるので驚かれるかもしれません。この城の石垣はとても珍しく、美しいものです。深緑色の縞模様がある緑泥片岩を使って積み上げられているからです。これらの石は阿波の青石としても知られています。同じ石垣の作り方は、蜂須賀氏が一宮城の後で築いた徳島城でも見ることができます。

本丸の石垣
緑泥片岩が使われています
徳島城の石垣

本丸の中には、若宮神社の小さな祠があるだけです。城主のための御殿の礎石が見つかったのは最近のことで、これも蜂須賀氏によって築かれました。ここからは、鮎喰川を含む周辺地域の景色もよく見渡すことができます。

本丸内部
若宮神社の祠
本丸からの眺め

「一宮城その3」に続きます。
「一宮城その1」に戻ります。

176.Ichinomiya Castle Part1

The largest mountain castle in Awa Province

Location and History

Ichinomiya Clan built it in Period of Northern and Southern Courts

Ichinomiya Caste was the largest mountain castle in Awa Province (what is now Tokushima Prefecture) on Shikoku Island. It is said that The Ichinomiya Clan first built the castle in the 14th Century during the Period of the Northern and Southern Courts. Many battles happened across the county, so warriors started to build mountain castles to protect themselves. After the governance of Awa Province got stable, The Ichinomiya Clan seemed to live in a hall at the foot of the mountain and used the castle in an emergency like other clans used to do.

The location of the castle

Motochika Chosogabe captured it in Sengoku Period

In the late 16th Century during the Sengoku Period, many battles happened again in Awa Province. Narisuke Ichinomiya, the lord of the Ichinomiya Clan, managed to survive under the Miyoshi Clan, the governor of the province, and partly thanks to Ichinomiya Castle. After that, he changed his mind to support Motochuka Chosogabe. Motochuka who was from Tosa Province in the south, invaded Awa Province in 1582. However, Narisuke was killed by Motochika probably because Motochika doubted Narisuke’s change of mind. Ichhoinomiya Castle was captured by Motochika.

The portrait of Motochika Chosogabe, owned by Hada Shrine (licensed under Public Domain via Wikimedia Commons)

Ichinomiya Castle was not only a large mountain castle but also Akui-gawa River flowed in front of the gate as a natural hazard. It also had a fountain and warehouses inside, so it could be besieged for a long time. It was also near the center of the province. For a warlord who aimed to govern Awa Province by power, it was necessary to get such a strong and good-located castle as soon as possible. Motochika sent one of his senior vassals, Tadazumi Tani, to Ichinomiya Castle to maintain it.

The aerial view of Ichinomiya Castle Ruins (from the location map of the park at the site)

Castle once became Capital of Awa Province

In 1585, the ruler, Hideyoshi Toyotomi sent over 100,000 soldiers to Shikoku Island to capture it. Ichinomiya Castle with about 10,000 defenders was besieged by about 40,000 attackers. The siege lasted for nearly one month and the castle was open as Motochika surrendered to Hideyoshi. Hideyoshi also sent one of his retainers, Iemasa Hachisuka as the lord of Awa Province. Iemasa chose Ichinomiya Castle as his home base, that meant the castle finally became the capital of the province. He built stone walls in the Main Enclosure on the top of the mountain though the castle had been all made of soil. He also built his Main Hall in the Main Enclosure and a building with a veranda in another enclosure, which might have been used for sightseeing.

The Portrait of Hideyoshi Toyotomi, attributed to Mitsunobu Kano, owned by Kodaiji Temple (licensed under Public Domain via Wikimedia Commons)
The statue of Iemasa Hachisuka at the ruins of Tokushima Castle
The stone walls at the Main Enclosure of Ichinomiya Castle

However, Iemasa moved his home base from Ichinomiya Castle to new Tokushima Castle facing the sea the next year in 1586. It is said this was due to Hideyoshi’s instruction to build the network of sea transportation. The situation rapidly changed after Hideyoshi’s unification of Japan. The peak of Ichinomiya Castle lasted for just one year. After that, the castle was considered one of the branch castles called the Awa Nine Castles while the governance of Awa Province was not stable. The castle was finally abandoned soon after the Law of One Castle per Province by the Tokugawa Shogunate in 1615.

To be continued in “Ichinomiya Castle Part2”