These two maps indicate the location of historical sites in the vicinity of Iidabachi and Yotsuya Stations. The sites offer vital insights about Tokyo’s history from the early modern to the modern period. The map on the left traces the path of early modem Japan’s “Five Routes,” which radiated out in all directions from central Edo’s Nihon-bashi Bridge, and indicates the location of the city’s entrance gates and post stations on its periphery. The second map is a jurisdictional map indicating the territories under the authority of the Edo City Governor. It shows that areas inside the Yamanate Line comprised the city center and that the city area extended over a vast space that stretched far east as present-day Kinshicho Station.
喰違（The Remains of Kuichigai Gate）外堀で唯一土塁を組み合わさせた門で、1612（慶長17）年に完成しました。現在も原形を確認できます。
赤坂門跡（The Remains of Akasaa-mon Gate）江戸城外郭門で、1639（寛永16）年に完成しました。石垣は一部現存し、福岡黒田家の刻印がみられます。
飯田橋周辺案内図
牛込駅（千代田区側）駅舎跡
牛込駅（千代田区側）駅舎跡 甲武鉄道時代、ここには牛込駅の出入口がありました。 現在でも、当時作られた駅舎の左右にあった石積み擁壁がそのまま残されており、見ることができます。 The Remains of Ushigome Station 石積み擁壁 高低差のある土地で土砂崩れを防ぐために設置し、石を積んだ壁。
牛込門枡形石垣跡の舗装表示 かって牛込門の枡形石垣があった位置が自然石舗装で表現されており、その大きさを体感することができます。 Remnants of Ushigome-mon Gate’s Stone Walls 枡形 「枡形」は石垣で箱形につくった城郭への出入口。
石に刻まれた印
石に刻まれた印 かつて牛込門の枡形石垣を構成していた石垣石が移設展示されています。 枡形石垣の整備を担当した徳島藩蜂須賀阿波守の刻印とみられるものが確認できます。 Inscriptions on the Stone
江戸城外堀跡散策案内図
江戸城外堀跡散策案内図
散策モデルルート Ａルート：「外堀散策ルート」Edo Castle’s Outer Moat
周囲14kmの江戸城外堀を史跡中心に巡ります。 This walk visits heritage sites along the outer moat’s 14-kilometer periphery Ｂルート：「江戸城内ルート」Edo Castle
牛込門から北の丸の田安門を経て旧江戸城本丸跡を巡ります。 Departing from Ushigome-mon Gate, this walk passes through the Northern Citadel’s Tayasu-mon Gate before visiting the remains of Edo Castle’s Inner Citadel. Ｃルート：「外堀水辺散策ルート」The Outer Moat Riverside Walk
神田川と日本橋川にある鉄道遺産などを巡ります。 This route visits sites along the Kanda and Nihonbashi Rivers relates to local railroad development.
江戸城 The History of Edo Castle 江戸城は、平安時代末の江戸氏居館、室町時代の太田道灌、戦国時代の小田原北条氏の支城として受け継がれました。豊臣秀吉は、北条氏を滅ぼすと、徳川家康を関東に移封しました。1590（天正18）年、徳川家康は江戸城に入城し、江戸城と城下町の建設を始めました。家康入城時の江戸城には石垣はなく土塁のみで、日比谷も入り江で日本橋・京橋辺りも海面と同じ高さの湿地でした。 家康は、まず城内の寺を出し本丸を拡張し、城下町の武家地、町人地を整えました。次に、本丸の南の台地を削り西の丸を造成し、その残土で日比谷入り江を埋め立てました。1603（慶長８）年、幕府を開き実権を握った家康は、天下普請として、城と城下町建設に諸大名を動員しました。同じ年に、神田山を崩して日本橋南の地域を埋め立て、市街地の造成と日本橋の架橋を行い、翌年には日本橋を起点とする五街道を整備しました。1606（慶長11）年には二の丸・三の丸と城郭の整備、石垣築造を進め、翌年には天守が完成しました。なお、天守は1657（明暦３）年に大火で焼失した後、再建されませんでした。 1868（明治元）年、明治天皇が江戸城に入り皇居となり、1960（昭和35）年、江戸城内郭の堀が「江戸城跡」として国の特別史跡に指定されました。このほか、「江戸城外堀跡」と「常盤橋門跡」が史跡に、外桜田門、田安門、清水門とそれぞれの櫓門が重要文化財に指定されています。
Edo Castle’s origins can be traced to the establishment of the Edo Clan’s estate in the late-Heian period. During the Muromachi period, it served as the location of Ōta Dōkan’s branch castle. Entering the Warring States Period, it was controlled by the Hōjō Clan’s and served as the site of their branch castle. When Toyotomi Hideyoshi eradicated the Hōjō Clan in the late-sixteenth century, Tokugawa Ieyasu was sent to their former territory in the Kantō region. In 1590, leyasu assumed control of Edo Castle and initiated the Castle’s reconstruction and construction of the surrounding castle town. At the time, there were no stone walls on the Castle site. The only remaining features of the Hōjō Clan’s branch castle were its earthen fortifications. In addition, the Hibiya area was an inlet and the Nihonbashi and Kyōbashi areas were low-lying wetlands. leyasu began the reconstruction effort by removing temples from the site, expanding the Castle’s inner citadel, and supervising the construction of the city’s commoner districts and warrior estates. He then removed portions of the plateau immediately south of the inner citadel and constructed the western citadel. In addition, the inlet in Hibiya was filled in using the earth removed from the plateau. In 1603, leyasu, who had by then seized national political authority and established a tent government, mobilized domainal lords from the across the country to construct the remaining portions of Edo Castle and the surrounding city area. The same year, Kanda Hill was leveled and earth removed from the Hill was used to fill in the southern portions of the Nihonbashi area. The area was then developed and Nihon-bashi Bridge was constructed. The following year, an archipelago-wide network of five overland circuits originating from Nihon-bashi Bridge was established. In 1606, the second and third citadels and castle tower were constructed and work continued on the stone walls surrounding the Castle. By the following year, the Castle’s main keep was complete. In 1657, however, the Castle was destroyed by a fire and had to be reconstructed. In 1868, the Meiji emperor moved to Edo Castle and it came to serve as the imperial palace. In 1960, Edo Castle’s inner moat was classified as Edo Castle’s official ruins and designated a National Heritage Site. In addition, remaining portions of the Castle’s outer moat and the ruins of Tokiwabashi Gate received designation as Historical Landmarks. Lastly, the box-shaped, two-story gatehouses at Sakurada-mon, Tayasu-mon, and Shimizu-mon Gates were designated as Important National Treasures.
牛込門枡形石垣跡の舗装表示
