The meaning of “mitsuke” as in Akasaka-Mitsuke (as well as Yotsuya-Mitsuke and others) is a fort gate established to guard a castle.
Along such gates are watchtowers to make sure “undesirables” do not get too close, and that’s why the kanji “mi” (watch) is used. So Akasaka, to a person in the Edo Period (1603-1867), might conjure up images of Edo Castle.
The mention of Akasaka to folks in the Showa Era (1926-1989) might make them think of the once popular song “Akasaka no Yo… (View original article)