Guide
Kiiji Castle Ruins (Kiijo Ato) is a Special National Historic Site located in Kiyama Town, Saga Prefecture, recognized as one of the oldest authentic mountain castles in Japan. It is said to have been constructed around the year 665 (the 4th year of the Tenji era) to strengthen the defense of Dazaifu. The site is characterized by a structure surrounded by approximately 4km of earthen and stone embankments that skillfully utilize the natural terrain. Today, the remains of ancient fortification techniques are preserved and managed as a site of immense historical value.
This site was built to strengthen the defense system centered around Dazaifu following the defeat at the Battle of Baekgang. Due to its structural characteristics, it is known as a "Korean-style mountain castle," exhibiting construction styles influenced by the Asian continent. The site also has a history of being used as "Kiyama Castle" during the medieval period, serving as a defensive stronghold from ancient to medieval times. It was designated as a National Historic Site in 1937 and became the first Special National Historic Site in Saga Prefecture in 1954.
The castle grounds contain earthen and stone embankments built to match the natural topography. In particular, the "water gate remains" built to block valleys and the traces of the castle gates are significant remains that demonstrate the advanced defensive technology of the era. Additionally, traces of approximately 40 buildings have been identified, with the "foundation stones" (礎石) that once supported the pillars now exposed. These are believed to have functioned as warehouses for storing weapons and food. Near the western earthen walls, a large group of "great foundation stones" (大礎石群) exists, providing clues to the scale of the massive structures that once stood there.
The Kiiji Castle Ruins are maintained as a hiking course that utilizes the natural terrain, offering different landscapes depending on the season. From near the summit, you can enjoy panoramic views of the surrounding area. In winter, the area near the summit is sometimes used for grass skiing. Visiting during the bright daylight hours allows for a detailed observation of the historical remains, such as the earthen walls, stone embankments, and foundation stones.
Visitors can enjoy hiking through the historical ruins. The route from the vicinity of the Kiyama Town Community Center toward the summit allows you to walk the path while observing the ancient castle structure. By walking the maintained courses, you can observe specific defensive features like the earthen walls and water gate remains up close. The summit area is also a place rich in nature, used for hiking and leisure.
The area around Kiyama Town features other historical sites and nature-rich spots. The castle ruins are integrated into a well-maintained hiking environment, allowing for a stroll that feels one with the surrounding nature. The summit area also serves as a functional space for grass skiing.