Kiishi Castle Ruins

Overview

The Kiishi Castle Ruins are an ancient mountain castle built in 665 AD (the fourth year of Emperor Tenchi's reign), simultaneously with Onoo Castle, making it one of Japan's oldest castles. Located 8 kilometers south of Dazaifu, Kiyama, where the ruins are situated, served as a southern defense stronghold protecting Dazaifu, primarily against potential threats from the Ariake Sea. This valley-enclosing mountain castle, approximately 3.9 kilometers in circumference, surrounds three valleys of Mount Kiyama (404 meters above sea level) and extends to its eastern peak (327 meters). It boasts an area of about 60 hectares. Most of the castle walls are earthen ramparts following the ridgelines, while the valley sections are blocked by stone walls. From the summit, you can enjoy panoramic views of Hakata Bay to the north, Kurume City and the Ariake Sea to the south, Chikushi City and Asakura City to the east, and the Habikino mountain range to the west. Excavations have uncovered the remains of approximately 40 stone foundation buildings, unearthed artifacts such as curved and flat roof tiles and pottery, and reservoir ruins at the summit. Four gates are believed to have existed, including two estimated locations. The remaining gate structures are the Kitamikado Gate and the Northeast Gate, located in the northern part of the castle. The South Gate and the Southeast Gate are estimated locations of gates in the southern part of the castle. The South Gate, serving as the main entrance to the castle ruins, and a series of water gate stone walls represent the castle's key water gate structures, along with the earthen ramparts. The water gate's drainage channel is one of the largest in Japan. Moreover, during the preservation and repair work of the water gate stone walls in 2015 (Heisei 27), three new drainage channels were discovered. Kiishi Castle is the only ancient mountain castle in Japan with more than four drainage facilities on the same stone wall face. On April 6, 2017 (Heisei 29), it was selected as one of the Continued 100 Famous Castles of Japan (number 184). Kiishi Castle Ruins offer a glimpse into ancient history and stunning mountaintop views, making it a recommended spot for history and nature enthusiasts alike.