Ushigome-mon Gate was located between the Ushigome-bori and Iida-bori Moats. A weir was constructed under Ushigome Gate in order to protect the earthen bridge that dammed the water in Ushigome-bori Moat and control the water level. When JR Iidabashi Station’s platform was relocated in 2017, remnants of stone paving believed to comprise a portion of the weir was discovered for the first time anywhere in the outer moat area. Photographs from the Meiji period contain images of the weir’s outfall and the sections of stone paving uncovered at the site are thought to have comprised a portion of the aqueduct located immediately in front of the outfall. Currently, the section of stone paving discovered is 2017 is preserved in its original location directly under the train platform. A portion of the platform’s surface has been modified in order to express the scope of the area that was covered by the stone paving. In addition, a portion of the paving removed from the site is on display in the plaza in front of the Station. It enables visitors to get a sense of the weir’s size. Unfortunately, no documents or records that describe the weir’s structure have been discovered. A similar type of structure known as the Sekiguchi Weir, however, which was constructed during the same period and transported water into the city from the Kanda River, provides us with some insights about weir technology and design. Located in present-day Bunkyo Ward’s Sekiguchi district, the arrangement of stone material used to construct the Sekiguchi Weir’s channel resembles that of the stone paving discovered along the outer moat in 2017. Also from the platform you can see the current waterway connecting the moats.
外堀の変遷 The Transition of the Outer Moat 外堀は江戸城防御の役割だけではなく、豊かな水辺空間として当時から江戸市民に親しまれ、名所絵などの浮世絵にも多く描かれました。「名所江戸百景」(広重」・1856(安政3)年—1858(安政5)年)には、市ヶ谷八幡の門前町が堀端に広がり賑わう景色が、外堀とともに描かれています。また、「富士三十六景」(広重・1858(安政5)年)には、御茶の水の懸樋下を、荷物を載せた船が往来する様子が描かれ、外堀が物資輸送路としても使われていたことがわかります。 明治期以降も外堀は景勝地として受け継がれました。1893(明治26)年、地域有志者からの寄付金により、四番町より市谷田町に通じる新道(現・新見附)開設願いが出され、甲武鉄道の延伸工事と一体で建設されることとなりました。 1894(明治27)年に開通した甲武鉄道と外堀の風景は絵葉書などに多く取り入れられました。1911(明治44)年には、牛込から喰違までの土手遊歩道を江戸城外堀として永久に保存するため公園とすることが計画され、1927(昭和2)年に牛込橋から新見附橋までの区域が「東京市立土手公園」として開設されました。なお、甲武鉄道や近代の牛込濠周辺の変遷については、駅舎2階に解説板を設置しています。
More than just a component in Edo Castle’s defense structure, the outer moat was also a verdant, waterside leisure space much loved by city residents. Depictions of the outer moat were frequently included in Tokugawa-era collections of woodblock prints. One famous collection entitled the One Hundred Famous Views of Edo, which was composed between 1856 and 1858 by the artist Hiroshige, includes a print depicting the outer moat and bustling, moat-side cityscape in the vicinity of Ichigaya’s Hachiman Gate. In a separate collection entitled Thirty-Six Views of Mount Fuji from 1858, Hiroshige depicts a cargo-filled boat passing under the outer moat’s Ochanomizu Acqueduct. This tells us that the moat was also a functional space used to transport goods around the city. After the 1868 Meiji Restoration, the outer moat continued to be considered a scenic area and a residential district was constructed on the moat’s Shinjuku side. Following the construction of the Köbu Railway in 1894, the Railway and surrounding outer moat area frequently came to be featured in postcards. In 1911, the authorities presented a plan to preserve Edo Castle’s outer moat as a public park. Specifically, the plan called for the construction of a pedestrian walkway along the embankment extending from Ushigome to Kuichigai. The plan came to fruition in 1927 with the construction of Tokyo’s Dote City Park, which extended from Ushigome to Shinmitsuke Bridge. For more information about the Kōbu Railway and Ushigome Moat’s modern development, please visit the history plaza on the second floor.
The Stone Used to Construct Ushigome-dobashi Bridge’s Weir The stone located next to this installation was used to construct the weir located under Ushigome-mon Gate’s earthen bridge. Portions of the weir were discovered during the construction of lidabashi Station. Documents detailing what was discovered at the site and describing the weir’ s appearance can be found at the exhibit on the platform at JR lidabashi Station. The exhibit is located in the vicinity of the site under Ushigome-bashi Bridge, where the weir was actually discovered.