SHIZUOKA - An excavation site at the ruins of the tenshudai tower base of Sumpu Castle is welcoming the general public, including tourists, to participate in the excavation work.
The unusual move for an excavation site kicked off this month.
The castle was constructed by Tokugawa Ieyasu, the founder of the Tokugawa shogunate, who built it as his residence in about 1585 before becoming shogun.
He moved back there in about 1607 after retiring from his position, ordering daimyo feudal lords across the nation to co-operate in major renovations of the castle.
The base of the tower is estimated to be 68 meters by 57 meters, larger than the 45-meter-by-41-meter one at Edo Castle.
It is considered one of the largest in the nation.
A panoramic view of the ruins of the tower base at Sumpu Castle, shot by a drone with permission.
A line of stone walls stretching from the foreground to the rear right are believed to be one side of the tower base, which is seen in the centre of this photo.
The excavation experience for the public took place inside this base.
An exquisite, opulent seven-story tower is said to have stood on the base as a symbol of the castle, but it was destroyed in a 1635 fire after Ieyasu's death.
Since it was not reconstructed, many details about the tower are no longer known.
The base was broken down during the Meiji era (1868-1912), and the remains were left underground.
The Shizuoka city government began research last year on the 9,400-square-meter site with the ruins of the tower base, aiming to confirm how much of the stone walls were left and their condition, as well as obtaining accurate academic data on them.
It plans to finish the research in February 2020, and will consider restoring the base and reconstructing the tower after examining the results of the excavation and the city's financial situation.
Excavation is conducted by experts on weekdays, and the general public is allowed to excavate on the second and fourth Saturdays and Sundays of each month until October this year.
Participants are required to wear a special helmet and carefully dredge dirt with a hoe-like tool called a "joren" under the instruction of an expert in an area where the public is not usually allowed to enter.
By providing this opportunity, the city hopes to boost general interest in the castle, while utilizing the excavation work itself as a tourism resource.
When the event was held for the first time on June 10, about 50 people from both inside and outside Shizuoka Prefecture participated.
Hayato Yamazaki, 12, from the city of Shizuoka, visited with his father, Keiichiro, 39. Hayato found a broken piece of tile that was likely from the Edo period (1603-1867).
"I took off my cotton work gloves and touched [the piece] with my bare hands. It was heavy, and I felt the history," the sixth grader said excitedly.
"We were under the hot sun, but working on a site that I usually just look at from far away was so much fun that I even forgot what time it was. I want to do this again."
The participation fee is ¥1,000 (S$13) for junior high school students and older, and ¥500 for fourth graders and older elementary school students.
Those younger than the fourth grade cannot participate.
Applications must be made over the phone in advance.