Inohana Castle Ruins — Attraction in Chiba

Inohana – Chiba Castle

Inohana Castle (亥鼻城, Inohana-jō), commonly referred to today as Chiba Castle (千葉城), is a reconstructed Japanese castle located in Chūō-ku, Chiba City, within Chiba Prefecture, Japan. The castle stands atop Mount Inohana, a small hill offering views over the city and the Tone River plain. Though the current structure is a modern reconstruction, the site itself carries centuries of samurai history closely tied to the origins of the Chiba clan, one of the most prominent warrior families in the early medieval period.

The original lords of Inohana Castle (Chiba Castle) were the Chiba clan.

Inohana Castle is believed to have been constructed in the late Heian period by Chiba Tsuneshige or his son Chiba Tsunetane, who were powerful samurai leaders descended from the Kanmu Heishi (Taira clan of Emperor Kanmu’s lineage). The Chiba clan played a crucial role in supporting Minamoto no Yoritomo and contributed significantly to the establishment of the Kamakura shogunate.

The castle served as the main stronghold and administrative center of the Chiba clan, who controlled much of the Shimōsa Province (present-day Chiba Prefecture). Although the original castle eventually fell into ruin during the Sengoku period, its historical legacy endures.

The current Chiba Castle standing today is a modern reconstruction built on the original Inohana site, serving as a museum and cultural monument commemorating the long and influential history of the Chiba family.

Thus, historically speaking, Inohana Castle (Chiba Castle) was indeed the residence of the Chiba clan.

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Historical Background

The original Inohana Castle is believed to have been built in the 12th century by Chiba Tsunetane, the founder of the Chiba clan, who served under Minamoto no Yoritomo, the first shōgun of the Kamakura shogunate. From this stronghold, the Chiba family exerted considerable influence over the Shimōsa region (present-day Chiba Prefecture) and became hereditary retainers of the Minamoto.

During the Muromachi period, the castle continued to serve as a local administrative and defensive center, but like many early fortifications, it fell into disuse and ruin over time. By the Edo period, when the Tokugawa shogunate centralized power, Inohana had long ceased to function as a military site.

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Modern Reconstruction

The current Chiba Castle keep (tenshu) is a modern reconstruction completed in 1967, built to commemorate the historical significance of the Chiba clan and to promote local cultural heritage. While not an accurate architectural reproduction of the medieval structure—since no detailed records of the original design remain—the building incorporates stylistic elements of traditional Japanese castles and serves as a local history museum.

Inside, visitors can explore exhibits dedicated to the Chiba clan, samurai arms and armor, and the regional history of Chiba City. The museum also provides educational materials on the clan’s role in supporting the Minamoto and shaping early Kamakura-era politics.

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Cultural and Scenic Significance

Inohana Castle Park is a popular destination for both locals and tourists. The area is especially famous during cherry blossom season (sakura), when the castle grounds are illuminated at night, creating a picturesque view reminiscent of classic Japanese landscape paintings. The castle’s elevated position makes it an ideal vantage point for observing the blend of historical and modern Chiba City.

Nearby landmarks include Chiba Shrine (千葉神社), dedicated to Myōken, the guardian deity worshiped by the Chiba clan, further emphasizing the site’s deep spiritual and cultural ties.

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Summary

Today, Inohana—Chiba Castle stands as a symbol of Chiba’s feudal heritage, a reminder of the clan whose name still defines the prefecture itself. Though reconstructed, the castle’s presence on Mount Inohana continues to connect modern visitors with Japan’s medieval past, making it both a cultural monument and a scenic retreat within the heart...

Inohana Castle is a great place to visit in Japan. It's a 10-15 minute walk from the monorail and is majestic to look at. Unfortunately, the museum was under renovation when I visited, but I still give this visit 5 stars. It deserves nothing less. The park around the castle is also a nice place to chill and just appreciate the...

猪鼻城跡はかつて鎌倉時代以来の千葉氏の城とされていました。 平常兼の子常重が大治元年(1126)、 上総国大椎(千葉市緑区) から千葉に本拠を移し、千葉という地名を名字とし、千葉常重と称しました。 常重の子・常胤は源頼朝を助け鎌倉幕府の創設に大きく貢献し、その功績で北は東北地方から南は九州地方まで多くの所領を得ました。 ところが､これまで猪鼻城跡で行われた発掘調査では、鎌倉時代の城や館の跡は見つかっていません。 ここにあった城は、室町時代後期 (戦国時代)に千葉氏の有力家臣にあたる原氏により城郭として整備されたものという説が有力で、火葬骨を納めた13世紀の壺が発 見されたことから、それ以前は墓域であったと考えられています。 郷土博物館西側の公園内を見回すと周囲が少し高くなっています。 これは土塁の跡です。 外からの攻撃をくい止めるために、 城内部の平地周辺に土を盛り上げて高くしていました。 その内側の郭と呼ばれた一画は城の中心で、江戸時代には本丸と呼ばれた場所にあたります。 北にある神明社のあたりは物見台の跡だと言われています。 そこからはかつて東京湾の海岸線や、足下にあった千葉の港を一望することができました。 本丸と物見台の跡との間が低くなっていますが、 これは防衛手段の一つとして設けられた空堀 (水のない堀)の跡です。 では、千葉氏が館としていた場所は実際にどこであったのでしょうか。 かつて方形の堀・ 土塁に囲まれて 「御殿跡」と呼ばれた現千葉地方裁判所の場所あたりではないかという説があります。 康正元年 (1455)、一族の馬加康胤・胤房が宗家の千葉胤直を攻め滅ぼした後、千葉氏が本拠地を千葉から本佐倉 (酒々井町・佐倉市)に移したことや、遺構や決定的な史料が見つかっていないこともあ...