Imori-bori Moat | Kanazawa Castle Park

Restoring the Outer Moat in Stages — Returning It to a Water-Filled Moat

History of Imori-bori Moat

The former Imori-bori Moat was the outer moat that surrounded the southwestern side of Kanazawa Castle. At its widest point, it measured approximately 40 meters across and more than 10 meters deep, and it once held water. The embankments consisted of gently sloped earthen banks, and at the southeastern end stood the stone wall of the Riko-yagura-dai Platform. After the abolition of the feudal domain system, in 1907 (Meiji 40), the former Imperial Japanese Army leveled the surrounding ground and filled in the moat, causing its water-filled appearance to disappear. In the postwar period, the filled area was repurposed and used as tennis courts.

Riko Turret Base

The Riko-yagura-dai Platform features neatly arranged, Rough Stone Stacking Technique that largely preserves the appearance created during major repairs in 1664 (Kanbun 4). Originally, it stood about eight ken (approximately 14.4 meters) high, but in 1907 the upper portion was demolished and the platform was buried along with the Imori-bori Moat.

Characteristics of the stone walls of the Riko-yagura-dai Platform

A nearly rectangular corner stone, finished with chisel work, with clearly defined, sharp-edged arrises.

The stone wall is primarily constructed using nunozumi masonry, characterized by continuous horizontal joints, with some sections employing otoshi-zumi stacking. Compared with the stones used for the Hishi-yagura Turret, the stones here are smaller in size.

Stone wall remains confirmed through archaeological excavation

Overview of the Step-by-Step Restoration Work

After the relocation of the tennis courts, archaeological investigations were conducted. Excavations carried out between 2003 and 2004 (Heisei 15–16) on the moat bottom and the turret platform clarified the fundamental shape of the Imori-bori Moat. Based on these findings, and under the guidance of the “Specialist Committee for the Restoration of Kahokumon and Related Structures of Kanazawa Castle,” the restoration design was finalized. Within the portion of the moat extending up to the city road, both the moat and the Riko-yagura-dai Platform were reconstructed. Water from the Tatsumi Waterway, after passing through Kenrokuen Garden, was introduced into the moat, restoring it as a water-filled moat with nearly the same water depth as in the past (approximately 5 shaku, or 1.5 meters).

Overview of the Restoration of the Riko-yagura-dai Platform

Approximately 900 stones were used in the restoration of the Riko-yagura-dai Platform. Of these, about 250 stones unearthed during archaeological excavations were given priority for reuse, while the remaining stones were quarried from Tomuro stone sources within Ishikawa Prefecture.

Main specifications of the restored Riko Yaguradai watchtower

Chronological Table of Events Related to Imori-bori Moat

1546	Kanazawa Gobo (a fortress and temple, also known as Kanazawa Mido) is built.
1580	Morimasa Sakuma becomes lord of Kanazawa Castle.
1583	Toshie Maeda becomes lord of Kanazawa Castle.
1602	The donjon is burnt down.
1615-1624	The previous moat is razed and a new moat dug around this time.
1631	A fire consumes the castle and the land around.
1644	The stone walls of the Riko Yaguradai watchtower are repaired. (A flood hinders the construction work.)
1662	An earthquake damages the stone walls of the Riko Yaguradai watchtower.
1664	The stone walls of the Riko Yaguradai watchtower are repaired.
1759	A fire consumes the castle and the land around. (Lead roof tiles and other discarded artifacts have been unearthed near the bottom of the moat.)
1871	Kanazawa Castle comes under the authority of the Ministry of the Military.
1907	The Imori moat is filled in. The high stone walls of the Hon-maru (main enclosure) collapse.
1947	Tennis courts are constructed for the 2nd National Athletic Meet.
1996	A city planning project is decided for Kanazawa Castle Park. Ishikawa Prefecture acquires the castle site, formerly used as the Kanazawa University campus.
1998	The tennis courts are transferred.
2001	The National Urban Greenery Fair in Ishikawa takes place.
2005	Imori Moat Park provisionally comes into service.
2006	A Plan for Kanazawa Castle Park Restoration and Development Project Phase 2 is formulated.
2010	Restoration of the Imori moat (phased process) and of the Riko Yaguradai watchtower is completed.