Preserving Japan’s cultural treasures: Rebuilding Marugame Castle’s stone walls

Cultural treasures are given their splendor when the highly developed artisanship of ancient times is met with the passion of today to preserve them for the next generation. The Tsumugu Project is dedicated to supporting those who endeavor to preserve Japan’s cultural treasures, and as such, will run a series of reports on efforts to repair or remake damaged cultural assets in various parts of the country, starting with a focus on Japanese castles. The first installment of “Preserving Japan’s cultural treasures” is on reconstructing the collapsed stone walls of Marugame Castle in Kagawa Prefecture.

The keep and the towering stone walls of a castle are symbols of power. Japan’s premier castles, with these assets, are cherished landmarks for the locals and a popular destination for tourists. However, the long history of such castles usually entails their struggle to counter the damage of war, devastation of natural disasters and deterioration over time. Accordingly, for artisans involved in repairing or reconstructing the local symbols today, doing their thing is somewhat historic, and they do with a lot of pride.

Marugame Castle (Kagawa Pref.)

     – Location: Marugame, Kagawa Prefecture (Shikoku island)

     – Construction: Began in 1579 (Keicho 2) and was finished 5 years later by the Ikoma clan who then ruled the Sanuki Province (current-day Kagawa Pref.). The stone walls were built sometime later during the early Edo period.

     – Type: Hirayama-jiro (Castle built on a small hill surrounded by a plain)

     – Features: Highest stone walls in Japan (reaches more than 60 meters above ground level). Listed as one of the “100 Fine Castles of Japan.” The keep (castle tower) is one of only 12 remaining original keeps in Japan.

     – Other names: Kameyama Castle, Horai Castle

(Source: Marugame city’s castle website)

Damaged by torrential rains, typhoon in 2018

The Marugame Castle in the city of Marugame in Kagawa Prefecture, sometimes referred to as the “stone castle,” is known for its tall-standing stone walls that reach 60 meters and more above ground level. Its majestic appearance makes it seem as if a fortified fortress is towering over the city center. Anyone strolling through the castle compound would likely be fascinated by the magnificent stone walls and their steep slope gradient.

In 2018, the stone walls were devastated by torrential rains that struck Western Japan and a tremendous typhoon that followed.

In July 2018, seven-meter-tall stone walls on the south side of Obikuruwa bailey collapsed over a width of 30 meters due to torrential rains. People could hear the ghastly sound of stones rubbing against each other. Stone walls 17 meters high on the southwest corner of sannomaru (literally, third circle; outermost region of a Japanese castle) collapsed sending up clouds of sand over an area that stretched out 30 meters in the north-south direction and 25 meters east-west. The locals were speechless.

The castle was originally constructed by the Ikoma clan in 1597 (Keicho 2). It was later taken over by the Yamazaki clan, and then the Kyogoku clan, but had always remained a strategic stronghold overlooking the Seto Inland Sea. In 1953, it was designated by the Japanese government as a historic site. As such, the castle has been a source of pride for the locals. They wanted the walls back, and upon request, the municipality took on to restore the stone structures applying traditional artisanship as well as up-to-date technology.

Traditional artisanship and new tech combined

At the site, fallen stones are thoroughly examined by skilled stone masons, who lightly strike the stones with their hammers and use their ears to find out if there are any hidden cracks. The stones are replaced with new ones if the damage is severe.

The number of stones they have to deal with count more than 6000. To put them back together, the experts have to decide what goes where. And to do that, they apply facial recognition technology to match the fallen stones with the stones in photos taken when the walls were up.

There have been unexpected findings in the process of reconstructing the stone walls. A part of an old stone wall that was built during the Edo period was found underneath the stone walls that collapsed. It was learned that the old walls were buried with soil before the new walls were erected on top of them. The old walls are on public view on site for the time being.

The reconstruction is scheduled to finish in fiscal 2024.

(From The Yomiuri Shimbun and other sources)