3. The Park Avenue Tunnel Used To Be A Train/Trolley Tunnel

Before the Park Avenue Tunnel was a north-bound passage for cars, it was formerly a train/trolley tunnel. Built in 1834, it was originally built for the New York & Harlem Railroad (NY&H) as an open cut, which ran steam engines as well as horsecars. In the 1850s, the open cut was bridged creating a tunnel to boost public safety by removing the train from Manhattan’s surface. The Park Avenue Tunnel became of the city’s oldest, accommodating trolley trucks and two-way traffic.

The staircases shown on the sides of the photo led customers to 37th Street and 4th Avenue, and passengers could board and detrain at this “flag” (by request) stop. Known also as the Murray Hill Tunnel, today it serves only northbound vehicular traffic while the tram tracks have long since been removed.