Yotsuya-sanchome Station serves Tokyo Metro's Marunouchi Line as stop M11, sitting near the boundary of Shinjuku and Yotsuya. The station opened in 1959, part of the Marunouchi Line's postwar expansion through central Tokyo. Its entrances connect to Route 20 (Shinjuku-dori), one of the city's older east-west arterials linking Shinjuku to the Kojimachi and Yotsuya districts. This particular entrance includes an elevator reserved for passengers heading toward the Shinjuku and Ogikubo directions, supplementing the stairways more commonly used at street level.
Yotsuya-sanchome Station Elevator Entrance, Tokyo Metro Marunouchi Line