Edo Castle stones found in Sagami Bay

Dily Yomiuri Online: Edo Castle stones found in Sagami Bay


YOKOHAMA--Four large stones believed to have been quarried on Izu Peninsula in Shizuoka Prefecture more than 400 years ago for the reconstruction and expansion of Edo Castle have been found in Sagami Bay.

The stones were found during an underwater survey jointly conducted by the Asian Research Institute of Underwater Archaeology and Ishichoba Iseki Kenkyu-kai, a study group comprising local government officials in charge of cultural properties, off Odawara, Kanagawa Prefecture, on Dec. 25.

The stones, believed to be among many quarried into usually square shapes, were found at a depth of two to five meters in areas about five to 30 meters off the coast. One of the stones is approximately 90 centimeters by 90 centimeters by 2 meters, about the same size as stones used in the central part of the castle grounds.

The stones are believed to have been quarried in 1606 in a project carried out by feudal lords under the order of the Tokugawa shogunate (1603-1867).

Some of the stones had holes called ya-ana that are thought to have been drilled into them to make them easier to quarry.

According to documents, about 3,000 ships carried stones quarried on Izu Peninsula to Edo for the reconstruction project.

The four recently discovered stones are highly likely to have fallen off a ship on the way to Edo (modern-day Tokyo) or washed out to sea when they were piled up on the coast.

"It [the finding of the stones] is an important initial step to learn how marine transportation--which until now has only been known through documents or drawings--was carried out," said Soichiro Kitagaki, head of Ishikawa Prefectural Research Institute of Kanazawa Castle and an expert on stone walls. "I hope traces of a port will also be discovered."