江戸時代、この土地には紀州徳川家、尾張徳川家、井伊家の屋敷があり、紀州徳川家と井伊家の境からは清水が湧き出していたため、この一帯は清水谷と呼ばれていました。なお、この清水を人工的に復元したのが現在の「清水谷公園」にある心字池です。
そして明治維新後の1878年（明治11年）、維新元勲三傑の一人の大久保利通が赤坂仮皇居へ出仕する途中に、この清水谷で石川県の士族である島田一郎らの手により、大久保利通が暗殺される「紀尾井坂の変」が勃発します。この事件は当時、世に衝撃を与え後の「清水谷公園」となった暗殺現場に、大久保利通哀悼碑が建てられました。
この「清水谷公園」は四季折々の景色を望めるのも特徴です。春には、園内に植えられた染井吉野やしだれ桜が花を咲かせ、公園に面した八重桜の並木道が辺りを桃色に染め上げます。また、秋になると紅葉や銀杏が色とりどりに色づき始め、季節の移ろいを感じられます。
大久保利通を取り巻く歴史と、それぞれの四季の表情を楽しめる「清水谷公園」。高層ビルに囲まれた場所でありながら都会の喧騒を忘れさせる「清水谷公園」は、お花見や紅葉狩り、歴史の名所巡り以外にも、園内のベンチに座って自然を感じながらリラックスするのもおすすめです。
千代田区観光協会ホームページより
During the Edo period, this area was home to the residences of the Kishu Tokugawa, Owari Tokugawa, and Ii families. Because clear spring water flowed from the border between the Kishu Tokugawa and Ii family residences, the area was known as Shimizu-dani (Clear Water Valley). The current Shinji Pond in Shimizu-dani Park is an artificial restoration of this spring.
Then, in 1878 (Meiji 11), after the Meiji Restoration, the Kioizaka Incident occurred in Shimizu-dani. Okubo Toshimichi, one of the three leading figures of the Restoration, was assassinated by Shimada Ichiro and others, samurai from Ishikawa Prefecture, while on his way to the temporary imperial palace in Akasaka. This incident shocked the world at the time, and a memorial monument to Okubo Toshimichi was erected at the assassination site, which later became Shimizu-dani Park.
Shimizu-dani Park is also characterized by its beautiful scenery throughout the seasons. In spring, the Somei Yoshino and weeping cherry trees planted in the park bloom, painting the area pink with double-flowered cherry trees lining the park's banks. In autumn, the maple and ginkgo trees begin to change color, allowing visitors to feel the changing seasons.
Shimizuya Park offers a glimpse into the history surrounding Toshimichi Okubo and the beauty of each season. Despite being surrounded by skyscrapers, Shimizuya Park offers a respite from the hustle and bustle of the city. Besides cherry blossom viewing, autumn leaf viewing, and historical site tours, it's also recommended to simply relax on a park bench and enjoy nature.
(From the Chiyoda Ward Tourism Association website)