The City Hall loop was originally the south terminal for the first line of the New York City subway, opened October 27, 1904. The station was built by the IRT (Interborough Rapid Transit), and is now part of the IRT Lexington Avenue Line.
The station is now abandoned due to infrastructural shortfalls as well as the proximity to the Brooklyn Bridge Station, which is the present terminal for the 6 train.
Although the station is abandoned, it can be seen from a downtown 6 train making a loop to the uptown track. New York Transit Museum members also have the privilege of visiting the station on tours.