Kikuichijo Castle

Overview

Kikuichijo Castle is an ancient Japanese mountain castle built on a plateau-like hill straddling Yamaga and Kikuchi cities in Kumamoto Prefecture. Excavations have revealed that it existed for approximately 300 years, from the late 7th to the mid-10th centuries. It's believed to have been built around the same time as Mizu-jo Castle, Ononojo Castle, and Motosujo Castle—structures constructed by the Yamato court to defend Wa (Japan) following its devastating defeat at the Battle of Hakusukinoe against the combined forces of Tang China and Silla. Located on the Yonemihara plateau at an altitude of approximately 90-171 meters, Kikuichijo Castle boasts a wall circumference of about 3.5 kilometers (including natural cliff faces) and covers an area of approximately 55 hectares. Located about 62 kilometers south of Dazaifu in a straight line, it's the southernmost ancient mountain castle. It sits approximately 30 kilometers inland from the mouth of the Kikuchi River, which flows into the Ariake Sea, in a fertile plain. The south side of the castle occupies a strategically important location along a presumed ancient official road. Excavations have uncovered numerous remains, including two uniquely octagonal structures (two structures built during two different periods), a total of 72 building sites, three gate sites, ramparts, water gates, and reservoirs. A wooden tag inscribed with characters and a gilt bronze standing statue of a bodhisattva of Baekje origin were also unearthed from the reservoir site. Initially, Kikuichijo Castle served as a military facility linked to Dazaifu, acting as a northern Kyushu defense stronghold along with Ononojo Castle and Motosujo Castle. It likely functioned as a logistical base and a defense against incursions from the Ariake Sea. After restoration periods, its role likely expanded to include food storage and as a base for controlling southern Kyushu. Kikuichijo Castle is believed to have been renovated into a base in northern Higo with administrative functions during the introduction of the Ritsuryo system at the end of the 7th century. It's a unique castle site, with excavations revealing modifications and changes in facilities linked to Dazaifu. Unlike other ancient mountain castles, which are located near kokufu (provincial capitals), Kikuichijo possessed its own administrative functions, making it a unique ancient mountain castle. From the late 8th century onwards, it is believed that it transformed into a facility specializing in material storage, with numerous warehouses, eventually leading to its demise. Today, the site has been developed into a historical park, with reconstructed buildings such as an octagonal drum tower, rice storehouse, barracks, and board-and-plank storehouses open to the public. It offers a chance to experience history while feeling the romance of the ancient era. Be sure to visit!