400-yr-old Edo Castle stone walls excavated at Imperial Palace in Tokyo

TOKYO – Stone walls from Edo Castle, believed to be around 400 years old, were discovered on the renovation site of a museum in the Imperial Palace.

The historical remains were excavated at the site of the renovation of Sannomaru Shozokan (Museum of Imperial Collections) in the east garden of the Imperial Palace in Tokyo’s Chiyoda district. The stone walls are not believed to have been repaired as they were first built at the beginning of the Edo period (1603-1867). A Chiyoda Township official said the finding “allows us to study stone-walling techniques.”

Stone walls of the approximately 400-year-old Edo Castle can be seen on April 13, 2021 on a construction site in the Imperial Palace in the Chiyoda district of Tokyo. (Mainichi / Natsuki Nishi)

According to the municipal administration, the stone walls were found near the Otemon Gate of the Imperial Palace. They run about 16 meters from north to south and are about 4 meters high – or about seven steps. It appears that they were part of the stone wall for the water-filled moat, and a ribbon-shaped white line indicating the flow of water at the time remains on its surface. It is believed that water rose up to the fourth through fifth tiers of the stone walls.

Researchers believe all of the stone walls were buried in the mid-17th century based on the loss of the top, the condition of the soil on the structure, and drawings from that period.

The field excavation investigation was carried out from November to December 2020. The researchers are studying and analyzing the excavated relics and the soil and will summarize the results in the future. The stone walls are then covered with earth again.



Stone walls of the approximately 400-year-old Edo Castle can be seen on April 13, 2021 on a construction site in the Imperial Palace in the Chiyoda district of Tokyo. (Mainichi / Natsuki Nishi)

Sannomaru Shozokan is expected to expand its storage and exhibition areas significantly, with the goal of being fully open to the public by 2025. A one year delay is now expected due to the impact of the excavation investigation.

(Japanese original by Takeshi Wada, Tokyo City News Department)

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